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  • Inorganic Chemistry  (1,032)
  • Industrial Chemistry
  • 1985-1989  (710)
  • 1950-1954  (598)
  • 1915-1919
  • 1987  (710)
  • 1953  (598)
Collection
Keywords
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  • 1985-1989  (710)
  • 1950-1954  (598)
  • 1915-1919
Year
  • 1
    Electronic Resource
    Electronic Resource
    Masthead (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987) 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270100101
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  • 2
    Electronic Resource
    Electronic Resource
    Liquid channelling on trays and its effect on plate efficiency (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 33-37 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: All the present experiments confirm that there is some liquid channelling on trays. Liquid channelling is extensive on trays of large diameters. It largely depends on the tilting of the plate, modifications of the inlet weirs and on non-uniform bubble cap spacing. Consequences of liquid channelling for plate efficiency are clear; the higher the degree of liquid channelling the lower the plate efficiency. However, own experimental and theoretical investigations indicate that plate efficiency never falls below the value of point efficiency. Therefore, liquid channelling only affects the crossflow on trays. Liquid channelling reduces the mass transfer performance to a similar extent as does the backmixing of liquid. Consequently, plate efficiency is not very sensitive to liquid channelling. Since the liquid is completely mixed in the downcomer, the effects of liquid channelling are restricted to a single tray. The behaviour of tray columns completely differs from that of packed columns, where the effects of liquid channelling are cumulative over the packed height. Consequently, trays represent a suitable design for columns of large diameters.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270100105
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  • 3
    Electronic Resource
    Electronic Resource
    Use of carbon dioxide in industrial organic syntheses (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 16-27 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Although carbon dixoide is important as an abundant carbonaceous raw material, so far, its utilization in chemical processes has been rather limited. This review covers the reactions of CO2 employed in industry, such as the production of urea, the Kolbe-Schmitt reaction, the synthesis of cyclic organic carbonates and the use of CO2 in methanol synthesis. Interesting recent developments in CO2 chemistry, such as the reactions catalyzed by transition metals, are also described. Apart from the synthesis of polymers and hydrocarbons, the production of oxygen-containing substances appears to be very profitable and attractive for future industrial applications. Not only can derivatives of formic and carbonic acids be produced but also longer-chain carboxylic acids and their derivatives by reactions of carbon dioxide with hydrocarbons such as alkynes, alkenes and 1,3-dienes.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270100103
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  • 4
    Electronic Resource
    Electronic Resource
    The separation of lecithin and soya oil in a countercurrent column by near critical fluid extractionLecture at the “Jahrestreffen der Verfahrens-Ingenieure”, Hamburg 25. to 27. Sept. 1985. (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 37-42 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The present contribution illustrates a way of developing a continuous separation process for near critical fluid extraction, on the example of separation of soya oil from lecithin. First, a suitable solvent was selected. Phase equilibria were measured in autoclaves. Operating conditions for a pilot plant were derived from the phase equilibrium data. The pilot plant experiments provided the necessary data for designing a production plant. Computer programs for phase equilibrium, stage to stage and mass and heat balance calculations were used in order to minimize the number of experiments. A production plant with a capacity of 500 t/a of raw lecithin was designed on the basis of experimental and computational results. A cost estimation, based on tenders, showed that it is more economical to produce lecithin by near critical fluid extraction than by conventional acetone extraction.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270100106
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  • 5
    Electronic Resource
    Electronic Resource
    Local energy dissipation in agitated turbulent fluids and its significance for the design of stirring equipment (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 56-63 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Ideal flow conditions are generally assumed for the reactor design. If stoichiometry, reaction mechanism and kinetics are known, the balance equations for the ideal flow tube, the ideal steady-state continuous stirred tank reactor or the ideal, completely mixed stirred batch reactor are often applied. In many cases, formal kinetics, which forms the basis of reaction modelling, is so uncertain that the idealization of the flow field can be accepted. In practice, however, deviations from the ideally calculated conversions, yields and product qualities, often occur. In these cases, it is necessary to consider the real flow conditions. In general, a distinction is made between macroand micromixing processes.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270100108
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  • 6
    Electronic Resource
    Electronic Resource
    Mass transfer area in different gas-liquid reactors as a function of liquid properties (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 1-15 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Using pilot-scale test plant, the interfacial area per unit volume was investigated in different gasliquid reactors, i.e. packed column, bubble column and free jet reactor. The interfacial area was studied as a function of liquid viscosity and of operating parameters. As a rule, identical test conditions were maintained in all the measurements, in order to obtain comparable results. The interfacial area was determined by chemical means using the sulphite system (a solution of sodium sulphite in water as model liquid and air as gaseous medium). The viscosity of the solution can be increased by adding carboxymethyl cellulose without significantly affecting the reaction kinetics. The addition of a surfactant to the sulphite system allowed comparative measurements at reduced surface tension. Based on a large number of measurements, the correlations of the interfacial area are expressed as power laws. The inclusion of experiments with a jet tube reactor and a stirring vessel allows an extensive comparison of all reactors. All tests were carried out with the same material system and the same method was used to determine the interfacial area per unit volume. Therefore, a comparison with respect to mass transfer is possible.
    Additional Material: 21 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270100102
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  • 7
    Electronic Resource
    Electronic Resource
    A new method for measuring local velocities of the continuous liquid phase in strongly aerated gas-liquid multiphase reactors (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 27-32 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A new measurement method for determining the local liquid-phase velocities in multiphase flows is presented. It is based on a tracer technique, using heat introduced into the flow, seemingly at random, instead of a material tracer. The input of heat pulses and measurement of temperature at an adjacent point is performed by small probes. As an intermediate result, the flow time distribution of the heat-labelled fluid elements is calculated on-line as a cross-correlation function between the pseudo-random input and the measured output signals. This calculation and the automatic control of measurements is carried out by a simple microprocessor unit. The device produced excellent results in gas-liquid flows at high gas throughputs and high liquid-phase velocities.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270100104
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  • 8
    Electronic Resource
    Electronic Resource
    Kinetics of removal of impurities from gases by high pressure adsorption (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 63-72 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Among other processes, adsorption is used for the removal of hydrogen sulphide from natural gases. Hereby, competitive adsorption of the different gas components plays an important role, e.g., that of carbon dioxide. Data of equilibrium loading and adsorption kinetics are required for the design of adsorbers, filled with molecular sieve. In order to obtain these data under the prevailing operating conditions, hydrogen sulphide was removed from gas mixtures H2S/CH4 and H2S/CO2/CH4, in a pilot plant, by adsorption on molecular sieve 5A. The equilibrium loading, the height of transfer zone, and the length of unused bed were determined from the measured breakthrough curves of H2S. With these data, the breakthrough time and the optimum process conditions were calculated for a practical example.
    Additional Material: 14 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270100109
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  • 9
    Electronic Resource
    Electronic Resource
    Reaction models for simulation of the oxidation of carbon monoxide in turbulent diffusion flames (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 43-55 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The oxidation of carbon monoxide by air in a turbulent flow was investigated under experimental conditions where the rates of turbulent mixing and of chemical reaction are comparable. For this purpose, carbon monoxide was admixed into the completely burnt gas of a natural gas flame operated with excess of air. Measurements of mean values of axial velocity, temperature and volume fractions of carbon monoxide and oxygen were compared with computational simulations involving the k - ∊ turbulence model and several turbulent reaction models for the oxidation of carbon monoxide. The comparison of measurements and numerical calculations demonstrated that the k - ∊ turbulence model is suitable for prediction of the turbulent flow field in the flow system investigated. Furthermore, it could be shown that one-variable turbulent reaction models, such as the flamesheet or the eddy-break-up model, cannot explain the measured carbon monoxide volume fraction profiles. Two-variable turbulent reaction models with a probability density function closure of the source term of the transport equation for the mass fraction of the chemical species result in a better agreement between the measured and simulated volume fraction profiles, particularly in predicting the clear influence of the initial temperature on carbon monoxide volume fractions. Weighting of the kinetic rate expression for the oxidation of carbon monoxide with different presumed probability density functions yields slightly different predictions of the carbon monoxide volume fractions, reflecting the assumed different character of turbulent fluctuations.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270100107
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  • 10
    Electronic Resource
    Electronic Resource
    Distillation columns with vertical partitions (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 92-98 
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    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Distillation columns with vertical partitions can separate a feed mixture into 3 or 4 pure fractions. Compared to other column arrangements, their investment costs and energy consumption are lower. Production columns show good results and are easily controlled. Conventional distillation columns produce only 2 pure product streams at the top and at the bottom of the column. Side products are contaminated by light or heavy components, depending on the location of the side stream in the rectifying or stripping section. This disadvantage is set aside by using a distillation column with a vertical partition. The internal separation wall prevents lateral mixing of liquid and vapour in the central part of the column, forming there separate feed and outlet sections. In the presence of a vertical partition, 3 or 4 pure fractions can be obtained in a single distillation step. This is particularly advantageous when heat sensitive components are to be separated. On account of good thermodynamic properties, the energy consumption is 20 to 35% lower than that of other distillation arrangements. The control behaviour is similar or better than that of conventional distillation columns.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270100112
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  • 11
    Electronic Resource
    Electronic Resource
    Advances in gas permeability measurements (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 86-92 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The Carman-Arnell equation relates the rate of flow of a fluid through a packed bed to the pressure drop across the bed. This equation is the basis for surface area determination by permeametry. It is found that the surface area measured at sub-atmospheric pressure varies with the bed porosity, so a porosity was selected where the rate of change was at a minimum. The study suggests that, at reduced pressures, the gas flow rate is a linear function of the mean pressure.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270100111
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  • 12
    Electronic Resource
    Electronic Resource
    Tentative modelling of spray-dry scrubbing of SO2 (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 104-112 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A 0.5 MW spray-dry scrubbing FGD pilot plant was used in the study of spray dryer performance over a wide range of operating conditions. Experimental findings were compared with a spray dryer model. During operation with large excesses of lime, the SO2 absorption was limited by gas phase diffusion. At operation with a shortage of lime, the rate limiting step was the dissolution rate of lime. In addition, the flow regime in a spray dryer can be best described as well mixed. The SO2 level in the flue gas was found to exert no direct effect on the efficiency of SO2 removal. The observed effects are attributed solely to the changes in the drying process, due to the inter-dependence of slurry composition and SO2 concentration.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270100114
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  • 13
    Electronic Resource
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    A new method for the prediction of liquid pulsed sieve-tray extractorsLecture at the Annual Meeting of Chemical Engineers, September 19th to 21st 1984 in Munich. (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 73-86 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: As a part of a research project on the mass transfer in liquid pulsed sieve-tray extraction columns (PSE), the diameters and hold-ups of the drops were measured: the drop size using a suction technique, with photoelectric detection, which was adapted to the special boundary conditions of the PSE; the integral hold-up by the pressure difference between the lower and upper parts of the column. Since experimental results cannot be described by known calculation formulae for the Sauter mean diameter and the hold-up, a new method of calculation was developed. It is phenomenologically based on high-speed photographs of the drop motion on a sieve tray. The mathematical-physical model allows the prediction of drop size and hold-up within certain limits, while the possible different operating regimes of the PSE, i.e. the mixer-settler and dispersion regimes can also be estimated.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270100110
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  • 14
    Electronic Resource
    Electronic Resource
    Continuous deasphalting of heavy petroleum residues with ethyl acetate (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 125-131 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: When crude oil is vacuum distilled, about 30% of the feed remain as low value residue. Hydrocracking can upgrade this residue into valuable light hydrocarbons. The hydrocracking could be optimized catalytically, if the residue were not to contain the metals vanadium and nickel that poison the catalyst. This contribution shows that continuous extraction of the residue with ethyl acetate yields a fraction with low metal content, while an asphaltene fraction with the remaining metal content is filtered off.
    Additional Material: 14 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270100116
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  • 15
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    Calculation of primary bubble volume in gravitational and centrifugal fieldsModified version of a paper presented at the meeting of “GVC Subject group: Mehrphasenströmung”, Kaiserslautern, February 20th, 1986. (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 99-103 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A one-stage model of the formation of primary bubbles is presented in which the bubble volume is deduced from an equilibrium of buoyancy, viscosity, inertia and surface tension forces. In contrast to the two-stage model, presented by Kumar and Kuloor, it was not assumed that the drag coefficient in bubble expansion can be described by the same constants as in the steady-state bubble ascent. The constants were adapted in such a way that the introduction of an additional bubble volume was not necessary. It was demonstrated that this model describes the bubble formation in gravitational and centrifugal fields equally well and, furthermore, is also applicable to structurally viscous liquids, provided that the effective shear gradient \documentclass{article}\pagestyle{empty}\begin{document}$$ \mathop {\rm \gamma }\limits^. = \frac{1}{6}({\rm \Delta \rho }gzd_{\rm B} /{\rm \eta }) $$\end{document} is calculated from the equilibrium of shearing and buoyancy forces. The model is based on the assumption of a constant volumetric flow rate during bubble formation and, for this reason, a minimum Froude number is necessary in analogy to the weeping limit for sieve plates. The normalized presentation permits simple operation. The possibility of applying the model to drop formation was confirmed by comparison of experimental values with those, predicted by the model.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270100113
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  • 16
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    New equipment for the determination of virial coefficients of pure substances and binary mixturesDedicated to Professor Dr. Kurt Hedden on the occasion of his sixtieth birthday (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 143-150 
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    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A new equipment for the measurement of virial coefficients of pure substances and binary mixtures is described. It consists of an improved modification of the set-up proposed by Eucken and Meyer in 1929. The development is based on a critical review of the existing methods particularly with respect to adsorption effects. In order to reduce the influence of adsorption on the accuracy of virial coefficients, an optimum range for gas density is recommended. The accuracy of the virial coefficients is better than 20 cm3 mol-1. The set-up was employed for the measurement of virial coefficients of acetone and hexane in the range from 352.95 to 393.85 K. The results are in excellent agreement with data published in literature. Furthermore, cross-virial coefficients of the binary system acetone/hexane were measured and interpreted.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270100118
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  • 17
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    Fouling of heat transfer surfaces (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 113-125 
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    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Fouling and/or scaling of heat transfer surfaces causes serious problems in industry. Prevention of fouling is therefore essential for technical (considerable deterioration of heat transfer) and also economic reasons (increased costs). In order to provide successful countermeasures, it is, however, necessary to obtain more detailed information on the physical, chemical and biological processes which produce fouling. Based on the already known fouling mechanisms, it is shown that a satisfactory prediction of fouling behaviour of heat exchangers is not yet possible. This contribution presents a physical model for the description of fouling, caused by sedimentation and crystallization. It is assumed that, during fouling, deposition and removal processes overlap. In order to verify the theoretical considerations, experiments were carried out on a test rig, which could also be used for field experiments. Aqueous CaSO4 solutions served as experimental liquids. A comparison of experimental and calculated fouling factors shows a satisfactory agreement.
    Additional Material: 23 Ill.
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    URL: http://dx.doi.org/10.1002/ceat.270100115
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  • 18
    Electronic Resource
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    Computer-aided design of tube-bundle heat exchangers (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 157-164 
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    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Based on a paper by Hein, a dimensioning program for tube-bundle heat exchangers with straight tubes and fixed tube sheets has been developed. The equipment to be dimensioned is tested at 14 critical points, with regard to permissible stresses. The optimum thickness of the tube sheet, the shell and channel are subsequently selected on the basis of economic criteria. Compared to dimensioning according to AD-data sheet, it is possible to save between 10 and 25% of production costs. With the aid of a finite-element (FE) program, complex structures such as heat exchangers can be calculated accurately. Several mesh-generation programs were written for the data input. The structure of a tube-bundle heat exchanger with straight tubes is generated with 3/D elements with only some geometrical data. An FE-calculation of a heat exchanger is explained with the aid of an example and stress analysis is presented.
    Additional Material: 19 Ill.
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    URL: http://dx.doi.org/10.1002/ceat.270100120
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  • 19
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    Simulation of fluid dynamics in a pulsed sieve plate columnLecture at the “Jahrestreffen der Verfahrensingenieure”, 17. to 19. September 1986 in Strasbourg. (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 151-157 
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    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The present contribution reports on a new method for the simulation of the dispersed phase behaviour in liquid-liquid extraction columns. The fluid dynamic description is based on a mathematical model which explicitly takes into account drop transport, break-up and coalescence mechanisms, via a drop population balance along the column. Application of the model requires some simple measurements on single drops in order to determine transport and break-up laws, which are required by the model, and possibly also coalescence parameters. In this study the model is applied to pulsed sieve plate columns. The specific example considered here is based on systematic studies on the determination of break-up rates from the corresponding probabilities of break-up and the generated daughter drop size distributions by means of high-speed photography. The validity of the model was subsequently tested by comparison with some experimental results from studies on two different pulsed columns 80 and 225 mm in diameter for the water/toluene system without mass transfer. The satisfactory agreement between the results justifies the use of such a method for the description of the behaviour of liquid-liquid extraction columns in a wide range of operating conditions. Furthermore, application of the model may help to dispense with long and expensive pilot tests.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270100119
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  • 20
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    Microbial desulphurization of coal - development and application of a slurry reactorPaper presented at the “Jahrestreffen der Verfahrensingenieure”, 17. to 19. September 1986 in Strasbourg (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 173-179 
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    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Microbial desulphurization of coal by pyrite oxidizing enrichment cultures containing predominantly Thiobacillus ferrooxidans was performed in an air-agitated slurry reactor, 20 l in volume. A model of microbiological and chemical reactions, occurring at various points within the coal, was set up taking into account the pore structure of the coal. The influence of parameters relevant to industrial processes, such as superficial gas velocity, particle size, initial pyrite concentration, and slurry density of the coal, on the conversion of pyrite was examined. Variation of the superficial gas velocity in the range of 0.01 to 0.04 m/s confirmed that the reaction is not controlled by oxygen transfer from gaseous to liquid phase. The rate of pyrite oxidation depends mainly on the accessibility of pyrite to micro-organisms which is determined by the particle size of the coal as well as the distribution of pyrite crystals in the coal matrix. The accessibility of pyrite to the micro-organisms is described by the ratio of effective to maximum microbial activity, measured as oxygen consumption. Starting with higher initial concentration of pyrite in the coal increases the oxidation rate, according to first order kinetics. Enhanced slurry densities lead to a decrease of pyrite conversion, in spite of higher pyrite concentration. The maximum pyrite oxidation rate was measured at 15% (v/v) slurry density and 25°C as 1800 mg Spyr/kg coal per day, or 360 mg Spyr/l reactor volume per day.
    Additional Material: 13 Ill.
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    URL: http://dx.doi.org/10.1002/ceat.270100122
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  • 21
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    Influence of electrolytes on the absorption of nitrogen oxide components N2O4 and N2O3 in aqueous absorbents (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 131-142 
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    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The influence of electrolytes, which are dissolved in the aqueous absorbent and do not react with nitrogen oxides, on the absorption kinetics of both these components was investigated experimentally. In addition to demineralized water, various salt solutions of different concentrations as well as sodium hydroxide solution were used as absorbents. The term H \documentclass{article}\pagestyle{empty}\begin{document}$ H\sqrt {k_1 D} $\end{document} for N2O4 and N2O3, which is important for the design of industrial absorbers, was determined as a function of composition and concentration of the absorbents. In the case of N2O4, the chosen measuring and evaluation methods permitted a separate determination of the rate constant k of the pseudo first order reaction and of the solubility H. The diffusion coefficient D of the gas in the absorbent can be obtained only by calculation. Experimental results showed that \documentclass{article}\pagestyle{empty}\begin{document}$(H\sqrt {k_1 D} )\,_{{\rm N}_{\rm 2} {\rm O}_{\rm 4} } $\end{document} decreases with increasing ionic strength I, however, without a clear indication of any ion-specific effects. This decrease does not appear to be caused simply by a reduction in solubility (salting out effect), or in diffusion coefficient, but at least, to the same extent, through a decrease of the rate constant k with increasing electrolyte content in the absorbent. The measurements permitted the determination of the gas-based salting out parameter for N2O4. The investigations on the absorption of N2O3 in water and in an Na2SO4 solution showed no experimentally detectable influence of dissolved salts on \documentclass{article}\pagestyle{empty}\begin{document}$(H\sqrt {k_1 D} )\,_{{\rm N}_{\rm 2} {\rm O}_{\rm 3} } $\end{document}. The numerical value of \documentclass{article}\pagestyle{empty}\begin{document}$(H\sqrt {k_1 D} )\,_{{\rm N}_{\rm 2} {\rm O}_{\rm 3} } $\end{document} is six times that of \documentclass{article}\pagestyle{empty}\begin{document}$(H\sqrt {k_1 D} )\,_{{\rm N}_{\rm 2} {\rm O}_{\rm 4} } $\end{document}.
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    URL: http://dx.doi.org/10.1002/ceat.270100117
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    Fluid dynamics and mass transfer in a bubble column with suspended particlesPaper presented at the Annual Meeting of German Chemical and Process Engineers (GVC, VDI) 1986, September 17 to 19 Strasbourg. (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 180-189 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Slurry bubble columns are widely used in biotechnology. Therefore, the effects of solid particles on fluidization characteristics, gas hold-up and volumetric liquid-side mass transfer coefficient were measured in a slurry bubble column (i.d. 0.14 m). The density and diameter of the suspended particles were similar to those applied in biotechnology with immobilized bacteria. Based on models of turbulence and of liquid circulation induced by rising gas bubbles, equations for critical gas velocity, gas hold-up and volumetric liquid-side mass transfer coefficient were obtained by dimensional analysis.
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    URL: http://dx.doi.org/10.1002/ceat.270100123
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    DIVA - a flow-sheet oriented dynamic process simulatorExtended version of a lecture presented by W. Marquardt at Jahrestreffen 1986 der Verfahrensingenieure, Strasbourg, 17. to 19. September 1986. (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 164-173 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The detailed dynamic simulation of coupled process units in chemical plants is gaining an increasing importance as a useful tool in plant engineering and operation. The outline of the program package DIVA (Dynamische Simulation verfahrenstechnischer Anlagen) which is currently under development is presented in the following. The dynamic plant equations and the corresponding Jacobian matrix are generated automatically. The full exploitation of sparse matrix techniques in combination with stiff ODE (ordinary differential equation) solvers allows an efficient solution of all the equations simultaneously. The possibilities offered by the simulator are demonstrated by the simulation of two laboratory plants.
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    URL: http://dx.doi.org/10.1002/ceat.270100121
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    Contact-free measurements of oxygen concentration in industrial flames by raman scattering (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 190-203 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Spatially resolved oxygen concentration measurements were performed in premixed hydrocarbon flames by using laser induced spontaneous Raman scattering. The measurements demonstrate the performance of a relatively simple pulsed laser Raman probe for fundamental combustion studies and also for the control of the equivalence ratio in flames (best spatial resolution: 0.2 mm3; theoretical detection limit: 0.8% of O2). Comparison of the results with those obtained by a mechanical suction probe (Magnos 2 T) confirmed a good agreement. At present, control of different stoichiometric conditions is possible at a minimum O2 concentration of 1.3%.
    Additional Material: 25 Ill.
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    URL: http://dx.doi.org/10.1002/ceat.270100124
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    Desorption delay in gas/liquid systems during vessel top ventingLecture at the European Two-Phase Flow Group Meeting, München, June 10 to 13, 1986.Dedicated to Prof. Dr. rer. nat. Heinz Harnisch on occasion of his 60th birthday (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 217-224 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: During the sudden unheated vessel top venting of initially saturated two-component gas/liquid mixtures, in which the gas is also extensively dissolved in the non-evaporating liquid phase, a solubility inequilibrium develops between the phases; re-equilibration can set in only after a so-called desorption delay time. Laboratory measurements of this delay time were under-taken with model mixtures of CO2 and water and viscous aqueous (Newtonian) solutions by high speed cinematography. The parameters of the experiments are relief cross-section, initial liquid level, pressure, temperature, and concentration. The shortest deley time obtained lasts approximately 75 ms. It differs substantially from the minimum boiling delay time previously measured with various refrigerants in the same test facility. The experimental results are correlated by a semi-empirical dimensionless power relationship, which includes all independent primary design variables generally availble in a physically consistent interrelationship. Reasonable extrapolations to other test conditions and aqueous two-component systems with an acceptable accuracy systems can therefore be expected.
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    URL: http://dx.doi.org/10.1002/ceat.270100126
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    Pressure drop and flooding in packed columns operating at high pressuresPresented at the joint session of the GVC Subject Group for “Thermal Separation of Gas and Liquid Mixtures” on 9th to 10th May 1985 in Bergheim/Austria. (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 231-242 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Correlations for pressure drop and upper capacity limit (flooding) are useful for the design of packed columns. Available correlations are based on the results of measurements made at atmospheric pressure. Extrapolation to higher pressures is not recommended. Therefore, systematic experimental investigations were carried out in a pilot plant at pressures of up to 100 bar. The experimental equipment and techniques, evaluation methods, and some characteristic experimental results are presented.
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    URL: http://dx.doi.org/10.1002/ceat.270100128
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    Investigation of entrainment in tray columns (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 224-230 
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    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: This paper describes a pilot plant for entrainment measurements on various types of column trays. The data obtained from different trays differ by up to a factor of 10. The measurements were compared with the theoretical model of Stichlmair. The Stichlmair entrainment diagram permits a fairly accurate prediction for most types of trays if the height of the two-phase layer is known. Prediction of the height and relative liquid hold-up in this two-phase system should be modified by a term reflecting the vapour flow profile, which requires further testing. These tests should examine the effect of tray spacing, fractional free area and, in particular, the influence of different media.
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    URL: http://dx.doi.org/10.1002/ceat.270100127
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    Gas/liquid interfacial area per unit volume and volumetric mass transfer coefficient in stirred slurry reactors (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 204-215 
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    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: In three-phase systems, where the liquid constitutes the continuous phase, solid is the catalyst and gas represents the dispersed phase, there are decisive criteria which have to be observed in reactor design. These are e.g. the interfacial area per unit volume between gas and liquid, the volumetric mass transfer coefficient and the mass transfer coefficient. The basic aim of the present work was therefore the investigation of these parameters in relation to the main influencing parameters. Process parameters stirrer speed and superficial gas velocity were varied as well as the physical properties such as liquid viscosity, solids concentration, particle diameter and a geometrical parameter, i.e. reactor diameter. The sulphite method was employed for the determination of these values. The test results confirmed the known relationships of power consumption and superficial gas velocity. An increase in the liquid viscosity leads to a decrease in all the tested values. In most cases, suspended solid particles lead to a lowering of the test values. The influence of the tank diameter on the plots of the test values against specific power consumption turned out to be invariant so that a scale-up of geometrically similar systems can be carried out at constant power consumption, superficial gas velocity and liquid viscosity.
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    URL: http://dx.doi.org/10.1002/ceat.270100125
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    Heat transfer in boiling of multicomponent mixturesPaper presented at GVC-Conference bAden-Baden (FRG) 25./26. April 1985. (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 242-248 
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    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Pool boiling data of multicomponent mixtures show that the heat transfer coefficients can be considerably lower than those of a corresponding pure fluid with the same physical properties as the mixture. The proposed model, which assumes maximum mass transfer resistance in the liquid boundary layer, is confirmed by the comparison between calculated and experimental data. The model allows the prediction of heat transfer coefficients in pool boiling of mixtures using only single component properties and vapour-liquid equilibrium data. Judging by experience with a number of different systems, the method should be sufficiently accurate for most practical applications.
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    URL: http://dx.doi.org/10.1002/ceat.270100129
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    Steam reforming of natural gas with intergrated hydrogen separation for hydrogen production (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 248-255 
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    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The development of heat resistant permeation membranes has opened up new possibilities for the conversion of fossil energy resources. In steam reforming of natural gas, such membranes even permit a direct production of hydrogen at high temperatures during the conversion of feed hydrocarbons. Further gas processing, such as required for reformer gas in existing hydrogen production processes, is not necessary. Due to continuous hydrogen discharge directly in the reformer tube, the chemical equilibrium of the occurring reactions becomes displaced towards the products, resulting in more favourable process conditions and, consequently, in improved by 36% utilization of the feed hydrocarbons. At the same time, the hydrogen yield increases by 44%. The heat required, which is provided by a high temperature reactor, is 17% in excess of that in conventional plants. It can be expected that the simplified process design will produce substantial cost advantages over the existing processes for the production of hydrogen.
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    Influence of temperature and properties of solids on the size and growth of bubbles in gas fluidized bedsPaper presented at the annual GVC meeting, Spetember 17-19, 1986, Strasbourg/France. (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 272-280 
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    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: In the present paper, models are developed for the description of coalescence and splitting of bubbles in gas fluidized beds. The distinction between slow and fast bubbles, which originates from the Davidson model of gas flow in and around a rising bubble, was found to be decisive for the modelling of coalescence processes. On the basis of the respective models, it is shown that a change in bed temperature does influence the mechanisms of both bubble coalescence and splitting. In cases of both slow and fast bubbles undergoing splitting, the theory predicts a decrease of bubble size with temperature whereas in the case of a non-splitting system with fast bubbles, typically encountered with Geldart type B particles, no significant temperature effect on bubble size is expected. The theoretical predictions are shown to be in agreement with own measurements as well as with the results of other workers.
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    URL: http://dx.doi.org/10.1002/ceat.270100133
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    Pressure pulsations in the piping of reciprocating pumps (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 262-271 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Pressure pulsations in hydraulic systems, generated by reciprocating pumps, can cause serious problems with regard to plant safety and reliability. In particular, fatigue problems arise in high-pressure piping systems. The available knowledge is not sufficient for an accurate computation of pressure peaks in the piping of reciprocating pumps. A number of calculation models are available which, however, neglect both fluid compressibility and friction. This contribution presents a calculation method which allows a precise modelling of various pump installations. Comparison of calculated and experimental data shows a good agreement and provides a validation of the computational model.
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    URL: http://dx.doi.org/10.1002/ceat.270100132
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    Oxygen and methane enrichment  -  a comprison of module arrangements in gas permeation (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 256-261 
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    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: In the separation of gaseous mixtures by gas permeation, it is in some cases impossible to achieve the desired product quality in a single stage and, therefore, several stages may be necessary. Multistage processes can be implemented by membrane modules arranged in the form of a cascade or by a membrane column design. On the basis of an economic analysis, this paper discusses different possible module arrangements for 2 cases, i.e. the enrichment of oxygen from air and the separation of methane from biogas. Present calculations indicate that, in the first case, two-stage cascades with or without recycle and, in the second case, one-stage cascade without recycle constitute the optimum module arrangements. However, depending on the selling price of the methane enriched gas, one- or two-stage cascades with recycle have to be considered. Finally, It was shown that, in the permeation of non-ideal gases, the Joule-Thomson effect has to be taken into account.
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    URL: http://dx.doi.org/10.1002/ceat.270100131
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    Particle velocity in a stratified two-phase flow between inclined parallel plates (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 281-289 
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    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Fundamental investigations of coalescence processes in settlers with plate packages for the separation of liquid-liquid dispersions prompted an analysis of the drop motion on the interface of a stratified two-phase flow. Therefore, a physical model was developed, which permits the calculation of drop velocity along the interface of an inclined trickling film. Starting from a balance of forces around a single particle, the model provides the equation of motion for a steady motion of single particles in a stratified two-phase flow. Several assumptions and considerations were necessary to solve this equation, such as taking into account the influence of the wall and of flow resistance. The model calculation assumes Newtonian liquids and laminar, smooth trickling films. A comparison with experimental results confirms that the drop motion behaviour is well reproduced.
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    URL: http://dx.doi.org/10.1002/ceat.270100134
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    Calculation of reactive extraction in countercurrent columns (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 291-296 
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    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The kinetics of extraction processes with chemical reaction was studied experimentally on the system copper/Acorga PT 5050 and quantified according to meaningful kinetic models. These were coupled with other models describing the behaviour of dispersions in columns in order to permit a computer aided simultation of reactive extraction. Thus, a better prediction of column performance is achieved.
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    Flow-induced vibrations of tube arrays in cross-flow (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 312-322 
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    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Existing heat exchanger design criteria do not satisfy the continually increasing requirements for greater efficiency or mass flux and energy throughput. Occasionally, failures appear even after only a few hours of operation, as shown in section 3. A long series of experiments, often carried out on original scale, did lead to the derivation of a large number of empirical expressions; however, physical explanations of the complex tube-failure interactions could not as yet be found. In contrast, experiments with a well defined simple model, whereby the tube deflections were recorded digitally and, at the same time, tube-fluid interactions were registered on a high-speed film, show that elementary “fluid transport mechanisms” control the stability behaviour of the heat exchanger tubes. Vibration excitation mechanisms such as “galloping”, “jet switching” and “whirling” (fluid elastic coupling) proved, with their characteristics, as typical for the vibration behaviour of single rows within the tube array, but not for the vibration phenomena of tube bundles.
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    Chemical technology of natural gas - its present state and prospects (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 297-305 
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    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Against the background of long-term availability of natural gas, its present technology and future prospects are described. Particular emphasis is put on the oxidative coupling of methane to C2+ hydrocarbons: (1) Catalyst development, activity, selectivity and deactivation as well as reactor operation are discussed; (2) a tentative process scheme is put forward and its economics evaluated with respect to ethylene production.
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    Conversion of organic oxygen compounds and their mixtures on H-ZSM-5 (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 323-329 
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    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The conversion of a number of alcohols, ethers, ketones, aldehydes, carboxylic acids, esters, and cyclic compounds and their mixtures on H-ZSM-5 at 673 K was investigated. These compounds can be easily converted to aromatic hydrocarbons if the C/H ratio of the molecule fragment, remaining after elimination of oxygen as water, is less than 0.62. At higher C/H ratios, coking of the catalyst increases, thus reducing its lifetime, a difficulty which can be overcome by hydrogenation of these compounds prior to their conversion over H-ZSM-5. A procedure is proposed for converting at least a part of organic waste chemicals to valuable products instead of burning them.
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    URL: http://dx.doi.org/10.1002/ceat.270100139
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    Rheology and flow of phosphate slurries (mine tailings) in pipesPresented by O. Scrivener at the “Jahrestreffen der Verfahrens-Ingenieure”, Strasbourg, September 17 to 19, 1986. (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 305-311 
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    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: An experimental study of the flow of phosphate mine tailings was carried out in order to characterize these suspensions of fine particles for pipeline transport. Rheological measurements with a rotating cylinder viscometer indicate a viscoplastic behaviour which can be represented by a Herschell-Bulkley or by a Casson model. The variation of the parameters of these models with solids concentration reveals a change in the behaviour at a concentration of 10 to 15%. The pressure drops were measured during flow in capillary tubes, in both laminar and turbulent regimes. The variation of the pressure drop coefficient (Fanning friction factor) as a function of the generalized Reynolds number confirms the validity of the employed rheological models. The results are in good agreement with measurements made in pipes of industrial size. The velocity profiles measured with a novel ultrasonic velocimeter demonstrate the influence of the rheological behaviour on the yield and wall stresses.
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    Rear surface deposition of fine particles on spheres  -  eddy deposition or electrostatic effects? (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 330-337 
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    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The aim of this investigation is to show the demarcation of two possible mechanisms for surface deposition of fine particles on the rear surface of single spheres. By means of single particle trajectory computation, based on numerically determined flow fields (Remax = 103), it is shown that the mere existence of a wake is not in itself sufficient to produce eddy deposition. In addition, the particle's motion must undergo a lateral transfer promoted by fluid trubulence, in order to effect eddy deposition commencing at a Reynolds number of about 100. On the other hand, rear deposition, influenced by electrostatic forces, especially by the Coulomb force, is possible at any Reynolds number. Consequently, for Reynolds numbers of less than 100, only electrostatic effects can produce rear surface deposition. In the range of high Reynolds numbers, the coexistence of both mechanisms is possible. Very high Reynolds numbers (Re 〉 103) and low Stokes numbers indicated the predominance of the electrostatic effect over eddy deposition, whereas at very high Reynolds numbers and medium to high Stokes numbers the electrostatic effect is only predominant in presence of high electrostatic charges.
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    Comparison of performance of an industrial VGO-treater with reactor model predictions (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 349-352 
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    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A simplified reactor model can be used for predicting the performance of an industrial VGO-treater. Laboratory-scale experiments performed on the same feed and catalyst as those in the industrial unit lead to a reactor simulation which agrees well with the data from this unit. In the laboratory experiments, it is possible to overcome the specific hydrodynamic problems of tricklebed reactors by appllying the catalyst dilution technique. Results obtained by this technique allowed the development of a reactor model which enables the user to simulate the adiabatic behaviour of the industrial reactor. In this way, the significant gap between the reaction temperature in the isothermal laboratory reactor and the WABT of the industrial adiabatic reactor can be bridged.
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    URL: http://dx.doi.org/10.1002/ceat.270100142
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    Kinetic studies on catalytic methanation by means of a concentration-controlled recycle reactor (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 361-367 
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    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The rate behaviour of multi-step reaction systems is difficult to model. Concentration-controlled investigations in a recycle reactor provide new tools for this purpose, e.g. the possibility to decompose a network into single reaction steps. Methanation of carbon monoxide over a supported Ni catalyst could be shown to be accompanied to a considerable extent by the shift reaction, and to a lesser extent by direct hydrogenation of carbon dioxide. Deactivation of the catalyst was measured at definite gas compositions. The two main steps show different responses to deactivation: Separable kinetics was found only for the methanation step. Power law rate equations were fitted to the rate data of the individual reaction steps to represent the main features of their kinetic behaviour. Some aspects of deactivation kinetics are also discussed.
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    Bubble flow in pressurized gas/solid fluidized beds (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 368-375 
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    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: This contribution presents the measurements of bubble behaviour in presence of A, B and D powders in a semi-industrial scale pressurized fluidized bed. Local measurements were taken at static pressures of 0.2, 1.0 and 2.5 MPa, using capacitance probes. Quartz sand with mean particle diameter of 157 μm was fluidized in small “two-dimensional” transparent equipment with Frigen R 115. In addition, pressure fluctuations in the bulk of the fluidized bed with inner diameter of 0.4 m were studied experimentally.
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    Theory and application of an alternative correlation flowmeter (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 353-360 
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    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Correlation flowmeters have been used in the scientific field for many years and are actually gaining greater commercial importance due to an increasing number of applications in industrial plants. The importance of the correlation method is based on the fact that essentially no alternatives exist for measuring velocity and mass flow rate in pneumatic conveyors. However, the hitherto employed transit time correlation method leads to results which are clouded by uncertainties. The commonly used theoretical model of the measurement process does not explain these effects satisfactorily. Therefore, the theory of non-intrusive flow sensors is reinvestigated from a physical standpoint. The derived model permits a discussion of the transit time correlation method in some detail. Furthermore, this model leads to an alternative sensor arrangement and signal processing scheme which makes it possible to measure the true mean velocities. Examples of experimental results are given.
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    Dynamics of distillation with high product puritiesExtended version of a paper presented by Dr. G. Wozny at the internal group meeting of the GVC Technical Committee on “Mass Transfer Processes” and “High-Pressure Process Engineering”, April 10 to 11, 1986. (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 338-348 
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    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: For the simulation of steady- and non-steady-state behaiour of separation columns, a simulation program was developed and employed for the calculation and optimization of methanol-water separation. The demand for increasingly higher purities and energy-saving optimization of plants results in complex column configurations and thus in complex control schemes. The number of possible control schemes was reduced on the basis of heuristic rules. By simulating the process, the optimum control and manipulative variables and measuring points were determined from the reduced number of control concepts. A control scheme was introduced. The model was verified by simulation of the dynamic behaviour of the process. The investigation included the effects of computing technique, time interval, model reduction and tray hold-up on the results. Thus, various effects and interactions were verified theoretically with respect to the robustness of the model. This was followed by a simulation of the non-ontrolled and controlled column. By implementing the controllers in the existing column program, the computer can predict the control parameters. These parameters were checked and corrected when the metahnol-ater column was put in operation. In the start-up phase, major problems were caused by the sensitivity and failure rate of density, throughput and pump measuring sensors. Feed impurities were another source of problems. Operation with high product purities is possible, with a side stream to discharge impurities.
    Additional Material: 11 Ill.
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    URL: http://dx.doi.org/10.1002/ceat.270100141
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    Vapour-liquid and vapour-liquid-liquid equilibria in ternary and quaternary systems of n-hexadecane, benzene, water and hydrogen, at elevated temperatures and pressures (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 382-389 
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    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Phase equilibria in the n-hexadecane-water-hydrogen and n-hexadecane-benzene-water-hydrogen systems were determined experimentally at temperatures between 200 and 350°C and pressures between 100 and 300 bar. At high water concentrations, three-phase equilibria were observed. Two-phase regions could be correlated with a modified Redlich-Kwong equation of state. The influence of interaction parameters on the calculated miscibility gaps was investigated. On application of mean interaction parameters, it is possible to calculate phase equilibria at different pressures or temperatures with the same set of parameters. In the ternary system, the three-phase regions could be calculated from the correlated binodal curves of two-phase regions. In the quaternary system, cross-sections through the vapour-liquid miscibility gap could be successfully correlated.
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    URL: http://dx.doi.org/10.1002/ceat.270100147
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    A differential model for a countercurrent extractor column with non-constant flow rates, interfacial area per unit volume and axial dispersion coefficients (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 375-382 
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    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: In the extraction literature, no attention has been given so far to differential calculation models for countercurrent extraction columns which take into account the changes in flow rates of the phases as a result of transferred mass, and which also reflect the variations in interfacial area per unit volume and in axial dispersion coefficients since these depend on the flow rates. The present contribution puts forward a formulation of such a model; this results in a set of non-linear differential equations with separated boundary conditions, representing the feeds at either side of the extraction column. This set of differential equations must be solved numerically. The model is illustrated by a sample calculation on the extraction of benzene with furfural. In this (realistic) example, the interfacial area per unit volume varies from bottom to top by a factor of 3. Ignoring this effect would obviously result in serious under- or overdesign.
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    Density of desublimed layers (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 405-410 
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    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Starting from the assumption that the growth of desublimed layers is governed mainly by heat and mass transfer, the authors present a model based on conditions in the diffusion boundary layer and suggest that the “hoarfrost”Hereafter the term frost will be used instead of hoarfrost. density depends on only one parameter. The discussion accounts for the process determining factors, i.e. the growth rate, mass transfer and gas concentration. The theoretical relationship is confirmed by the authors' own experiments on two systems and data from literature. The relationship can be established by a few laboratory experiments and permits the calculation of frost density and of associated variables, thus facilitating the optimization of desublimator design.
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    URL: http://dx.doi.org/10.1002/ceat.270100150
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    Progress in the kinetics of coal and char gasificationDedicated to Professor Dr. Kurt Hedden on the occasion of his sixtieth birthday (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 411-419 
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    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: This contribution reviews the work performed mainly at Bergbau-Forschung during the past few years. First, it deals with the quantitative description of gasification kinetics, taking into account the pressure of the gasifying agent and partial pressures of product gases. Thereby, a method and quantitative data are provided for the calculation of reaction rates for uncatalyzed and potassium-catalyzed gasification, on the example of chars from high volatile bituminous coals. In addition, a method for characterization of internal surface area by oxygen chemisorption with respect to char reactivity has been improved. Progress has also been achieved in the assessment of the impact of pyrolysis conditions, especially the time-temperature profile during char formation, on its chemical activity during subsequent use.
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    Scale-up of power consumption in agitated ball millsLecture at the “Jahrestreffen der Verfahrens-Ingenieure”, Strasbourg, September 17 to 19, 1986. (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 398-404 
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    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Previous investigations have shown that the specific energy input is the overall parameter of influence on product size during communition in agitated ball mills, from laboratory up to industrial scale. The specific energy input is the introduced energy related to the amount of comminuted material. This parameter can be used for mill scale-up. Consequently, a method had to be found of introducing power into the mill so as to obtain a given specific energy input. For this purpose, stirring tests with purely Newtonian liquids were carried out in absence of solids and hence, without comminution. Mathematical models are presented which describe the power consumption in agitated ball mills in absence of grinding beads. In addition, tests with grinding beads filling were also performed, leading to scale-up guidelines with respect to power consumption. Finally, the influence of size and material of grinding beads was investigated.
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    Modelling of adsorption in cyclic operation of a PSA plant for H2 recoveryLecture by H. Brüggendick at the “Jahrestreffen der Verfahrensingenieure”, 17. to 19. September 1986 in Strasbourg. (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 390-398 
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    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A pressure swing adsorption process for hydrogen recovery from coke oven gases comprises the steps of adsorption at pressures above 6 bar, cocurrent and countercurrent depressurization, purging with hydrogen at ambient pressure and repressurization. The process was investigated in the cyclic mode, on a laboratory scale, using an adsorber filled with 1.3 litres of carbon molecular sieve. Based on the test results of concentrations and pressures within the adsorber during complete cycles, a pseudo-homogeneous model was developed for the adsorption step. Adsorption equilibrium parameters were determined by separate measurements, while the transport parameters were evaluated by fitting the experiments of the fixed bed adsorber. It was possible to consider the residual load, resulting from an incomplete regeneration, by the assumption of a load distribution in the inlet region of the adsorber.
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    URL: http://dx.doi.org/10.1002/ceat.270100148
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    Homogeneous non-equilibrium two-phase critical flow modelPresented by J.J. Schröder at the “Jahrestreffen der Verfahrens-Ingenieure”, Strasbourg, September 17 to 19, 1986. (1987)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 10 (1987), S. 420-426 
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    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: An important aspect of nuclear and chemical reactor safety is the ability to predict the maximum or critical mass flow rate from a break or leak in a pipe system. At the beginning of such a blowdown, if the stagnation condition of the fluid is subcooled or slightly saturated thermodynamic non-equilibrium exists in the downstream, e.g. the fluid becomes superheated to a degree determined by the liquid pressure. A simplified non-equilibrium model, explained in this report, is valid for rapidly decreasing pressure along the flow path. It presumes that fluid has to be superheated by an amount governed by physical principles before it starts to flash into steam. The flow is assumed to be homogeneous, i.e. the steam and liquid velocities are equal. An adiabatic flow calculation mode (Fanno lines) is employed to evaluate the critical flow rate for long pipes. The model is found to satisfactorily describe critical flow tests. Good agreement is obtained with the large scale Marviken tests as well as with small scale experiments.
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    Die Oxidfluoride des Niobs und Tantals (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 544 (1987), S. 122-126 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Oxidefluorides of Niobium and TantalumThe reaction of NbF5 with SiO2 (silica glass ampules) at 310°C or with SiO2 (Aerosil) at 180°C always leads to NbO2F. To the contrary the reaction with laboratory glass (Jenaer Geräteglas) at 130°C leads to NbOF3.TaF5 reacts in silica glass ampules at 400°C by formation of TaO2F, however at 300°C or 260°C by formation of TaOF3.Silica glass did not react with NbF5 at 130°C, however Nb2O5 and NbF5 gave at 130°C in silica glass ampoules NbOF3. Similarly, TaF5 and Ta2O5 or TaO2F formed at 260°C in nickel ampoules TaOF3. The chemical and the thermochemical behaviour of oxidefluorides have been investigated.The compounds NbOF3 and TaOF3 are isomorphic. Lattice constants are mentioned.
    Notes: Die Reaktion von NbF5 mit SiO2 (Quarzglasampullen) bei 310°C oder mit SiO2 (Aerosil) bei 180°C führte stets zu NbO2F. Dagegen reagierte NbF5 mit Jenaer Geräteglasampullen bei 130°C zu NbOF3. TaF5 reagierte mit Quarzglasampullen bei 400°C unter Bildung von TaO2F, bei 300 oder 260°C jedoch unter Bildung von TaOF3.Quarzglas reagierte bei 130°C nicht mit NbF5, jedoch gaben Nb2O5 und NbF5 bei 130°C in Quarzglasampullen NbOF3. Analog bildeten TaF5 mit Ta2O5 oder TaO2F bei 260°C in Nickelampullen TaOF3.Das chemische und thermische Verhalten der Oxidfluoride wurde untersucht.Die Verbindungen NbOF3 und TaOF3 sind isomorph. Gitterkonstanten werden angegeben.
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    Zum Ligandenaustausch an TcNX4--Komplexen (X = Cl, Br) (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 544 (1987), S. 167-180 
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    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Ligand-Exchange Reactions on TcNX4- Complexes (X = Cl, Br)Ligand exchange reactions on the nitridotechnetium(VI) compounds (Bu4N)TcNCl4 and (Bu4N)TcNBr4 are reported. The use of various organic ligands having different donor atom sets produces TcV nitrido complexes. The reaction of (Bu4N)TcNCl4 with (Bu4N)TcNBr4 is characterized by the formation of TcVI complex species with mixed Cl/Br coordination spheres. EPR detection of the mixed-ligand complexes results in a well-defined dependence of the EPR parameters on the composition of the first coordination sphere of the complexes.
    Notes: Es wird über Ligandenaustauschreaktionen an den Nitridotechnetium(VI)-Komplexen (Bu4N)TcNCl4 und (Bu4N)TcNBr4 berichtet. Dabei entstehen bei Verwendung organischer Liganden mit unterschiedlichen Donoratomen Nitridokomplexe des Technetiums(V). Bei der Reaktion von (Bu4N)TcNCl4 mit (Bu4N)TcNBr4 in unterschiedlichen Mischungsverhältnissen entstehen Komplexspezies des TcVI mit gemischter Cl/Br-Koordinationssphäre. Bei Untersuchungen mittels EPR-Spektroskopie konnte für die gebildeten Gemischtligandkomplexe eine definierte Abhängigkeit der Spektrenparameter von der Zusammensetzung der ersten Koordinationssphäre nachgewiesen werden.
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    Methoxostibane. Struktur und Schwingungsspektren (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 544 (1987), S. 181-191 
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    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Methoxostibanes. Structure and Vibrational SpectraThe crystal and molecular structure of Sb(OMe)3 (1) was determined by X-ray analysis. 1 forms layers in which the Sb atoms are coordinated by 6 O atoms. The halogenomethoxostibanes SbCl(OMe)2 (2), SbCl2(OMe) (3), SbBr(OMe)2 (4), SbBr2(OMe) (5), and SbI(OMe)2 (6), which were partially prepared for the first time, as well as 1 were examinated by vibrational spectroscopy. The spectra were discussed in view of the structure in the solid state. 2, 4, and 6 posses a structure similar to that of 1 with Sb2O2 and Sb2Cl2 ring systems. The coordination number of Sb is 6. In 3 and 5 there are also Sb2O2 and Sb2Hal2 rings, but the structures are probably different from those of 2 and 4.
    Notes: Die Kristall- und Molekülstruktur von Sb(OMe)3 (1) wurde mittels Röntgenstrukturanalyse bestimmt. 1 bildet ein Schichtengitter, bei dem die Sb-Atome durch O-Atome 6fach koordiniert sind. Die z. T. erstmals dargestellten Halogenomethoxostibane SbCl(OMe)2 (2), SbCl2(OMe) (3), SbBr(OMe)2 (4), SbBr2(OMe) (5) und SbI(OMe)2 (6) sowie 1 wurden schwingungsspektroskopisch untersucht. Die Spektren wurden im Hinblick auf die Struktur im festen Zustand diskutiert. Danach zeigen 2, 4 und 6 eine zu 1 vergleichbare Struktur mit Sb2O2- und Sb2Hal2-Vierringen und Sb der KZ 6. Auch in 3 und 5 liegen Sb2O2- und z. T. Sb2Hal2-Vierringe vor. Die Strukturen dürften sich allerdings von denen von 2 und 4 unterscheiden.
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    Die elektrochemische Reduktion von CSSe und CSe2 in Dimethylformamid: Heterocyclische 1,2-Dichalkogenolate und ihre Koordinationschemie (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 544 (1987), S. 199-208 
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    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Electrochemical Reduction of CSSe and CSe2 in Dimethylformamide: Heterocyclic 1,2-Dichalcogenolates and their Coordination ChemistryStarting from carbon diselenide or carbon selenidesulfide the electrochemical preparation (electrosynthesis) of heterocyclic dichalcogenolates C3X52- (X = Se: dsis; X = S/Se: C3SxSey2-) is outlined. The 1,2-dichalcogenolate compounds were isolated and characterized as dibenzoyl derivatives. Bis- or tris-chelates of general type Am[M(C3X5)n] (with A = Bu4N+, Ph4As+; M = ZnII, PtII, PdII, NiIII, CuIII, AuIII, InIII; X = Se, S/Se; m = 1, 2, 3; n = 2, 3, respectively) are available directly from methanolic solutions of the dibenzoylates after hydrolytic cleavage of the latter with sodium methanolate. In addition bis-chelates Bu4N[Ni(C3X5)2] (X = Se, S/Se) have been characterized by cyclovoltammetry and epr spectroscopy and compared with the corresponding all-sulfur ligand compound Bu4N[Ni(dmit)2] (X = S). Arguments are given for the fact that the allselenium ligand dsis (X = Se) yields the CuIII or NiIII chelate at once whereas with dmit using identical conditions the metal(II) compounds are formed.
    Notes: Ausgehend von Selenkohlenstoff und Selenschwefelkohlenstoff wird die elektrochemische Darstellung heterocyclischer Dichalkogenolate C3X52- (X = Se: dsis; X = S/Se: C3SxSey2-), die als Dibenzoylverbindungen isoliert und charakterisiert werden, beschrieben. Aus den mit Alkalimethanolat erhaltenen Verseifungslösungen dieser Dibenzoylverbindungen sind Metall-bis- und -tris-Chelate der heterocyclischen 1, 2-Dichalkogenolate vom Typ Am[M(C3X5)n] (A = Bu4N+, Ph4As+; M = ZnII, PtII, PdII, NiIII, CuIII, AuIII, InIII; X = Se, S/Se; m = 1, 2, 3; n = 2, 3) unmittelbar zugänglich. Cyclovoltammetrisch und mittels EPR werden die Nickel(III)-Verbindungen Bu4N[Ni(C3X5)2] (X = Se, S/Se) charakterisiert und der analogen Schwefelverbindung Bu4N[Ni(dmit)2] (X = S) gegenübergestellt. Für die bei der Chelatisierung mit dsis (X = Se) beobachtete Metall(II)-Metall(III)-Oxydation bei Kupfer und Nickel werden Argumente erörtert.
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    Über die pH-Abhängigkeit der 31P- und 31C-NMR-Spektren von Cyclohexan-, Cyclohexen- und Benzenphosphonsäuren (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 544 (1987), S. 232-240 
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    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: About the pH-Dependence of 31P and 13C NMR Spectra of Cyclohexane-, Cyclohexene-, and Benzenephosphonic Acids31P and 13C chemical shifts as well as P—C coupling constants of phosphonic acids are affected by the pH of the investigated solutions. This dependence was measured for aqueous solutions of cyclohexane-, cyclohex-1-ene-, cyclohex-2-ene-, cyclohex-3-ene-, and benzenephosphonic acid. It is shown that the 31P chemical shift and various 13C chemical shifts are well suited for the determination of pKa values.
    Notes: 31P- und 13C-chemische Verschiebungen wie auch P—C-Kopplungskonstanten von Phosphonsäuren werden entscheidend vom pH-Wert der untersuchten Lösungen beeinflußt. Für Cyclohexan-, Cyclohex-1-en-, Cyclohex-2-en-, Cyclohex-3-en- und Benzenphosphonsäure wurde die pH-Abhängigkeit von δP, δC und JPC ermittelt. An Hand von Beispielen wird gezeigt, daß sich die 31P-chemische Verschiebung und ausgewählte 13C-chemische Verschiebungen gut zur Bestimmung von pKS-Werten eignen.
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    Acetylenbis(phosphonigsäurediamide), -bis(phosphonigsäurefluoridamide) und -bis(phosphonigsäuredifluorid) (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 545 (1987), S. 47-55 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Acetylene Bis(Phosphonous Diamides), Bis(Phosphonous Fluoride Amides), and Bis-(Phosphonous Difluoride)Synthesis and properties of the acetylene bis(phosphonous diamides) 2-5, the acetylene bis(phosphonous fluoride amides) 6 and 7 and of acetylene bis(phosphonous difluoride), 8, are described. The result of the X-ray structural analysis of 2 is reported.
    Notes: Synthese und Eigenschaften der Acetylenbis(phosphonigsäurediamide) 2-5, der Acetylenbis(phosphonigsäurefluoridamide) 6 und 7 sowie von Acetylenbis(phosphonigsäuredifluorid) 8 werden beschrieben. Von 2 wird das Ergebnis der Röntgenstrukturanalyse mitgeteilt.
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    URL: http://dx.doi.org/10.1002/zaac.19875450206
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    Übergangsmetallkomplexe [Et2P(S)NR]M/n, Vierringchelate mit Thiophosphinsäure-Organylamidato-Liganden [1] (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 545 (1987), S. 75-82 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Transition Metal Complexes [Et2P(S)NR]M/n, Chelates containing 4-membered Rings and Phosphinothioic-organylamidato LigandsPhosphinothioic-organylamidato complexes [Et2P(S)NR]M/n (R = Me, Et, tBu, cHex, Ph; M = TiIII, VIII, CrIII, CoII, ZnII) are obtained by reaction of metal halides with [Et2P(S)NR]Li or from ZnEt2 and Et2P(S)NHR. In contrast to the analogous phosphinothioic complexes [R′2P(S)X]M/n (X = O, S, Se) they are extremely hydrolyzable. The ligand field parameters Δ and β of Et2P(S)NR- are found to be similar to those of R′2P(S)S- indicating a low ligand field strength and a strong nephelauxetic effect. In contrast to [R′2P(S)O]2M (M = Co, Zn), which are highly polymerised, there is only a weak tendency of the corresponding tetrahedral phosphinothioicorganylamidato complexes to form ligand bridges.
    Notes: Thiophosphinsäure-organylamidato-Komplexe [Et2P(S)NR]M/n (R = Me, Et, tBu, cHex, Ph; M = TiIII, VIII, CrIII, CoII, ZnII) erhält man durch Umsetzung von [Et2P(S)NR]Li mit Metallhalogeniden oder aus ZnEt2 und Et2P(S)NHR.Im Gegensatz zu den analogen Thiophosphinaten [R′2P(S)X]M/n (X = O, S, Se) sind sie äußerst hydrolyseempfindlich. Die Ligandenfeldparameter Δ und β von Et2P(S)NR- sind denen von R′2P(S)S- ähnlich und lassen eine nur geringe Ligandenfeldstärke und einen starken nephelauxetischen Effekt erkennen. Im Gegensatz zu den Komplexen [R′2P(S)O]2M (M = Co, Zn), die hochpolymer sind, zeigen die entsprechenden tetraedrischen Komplexe mit Thiophosphinsäureorganylamidato-Liganden nur eine geringe Tendenz zur Bildung von Ligandenbrücken.
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    A thermodynamic model of The Hg0.8Cd0.2Te-Iodine Transport System. II. Source material composition within the homogeneity range (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 545 (1987), S. 109-117 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Ein thermodynamisches Modell des Hg0,8Cd0,2Te-Iod Transportsystems. II. Ausgangsmaterial innerhalb des HomogenitätsbereichesDas Näherungsmodell zur Berechnung von Diffusions-Transportraten des Hg0,8Cd0,2Te-Iod-Systems [1] wurde für Zusammensetzungen des Ausgangsmaterials innerhalb des Homogenitätsbereiches erweitert. Dazu wurde die Hg-Leerstellenbildung berücksichtigt und experimentell ein Überschuß an elementarem Hg in System benutzt. Die gute Übereinstimmung von berechneten und beobachteten Transportraten (senkrechte Ampullenstellung, höhere Temperatur oben) bestärkt die Richtigkeit dieses Modells.
    Notes: The first order approximation model for the computation of diffusion limited mass transport rates for the Hg0.8Cd0.2Te-iodine system, based on Te-saturated source materials [1], was extended to include source compositions within the homogeneity range. This required the consideration of Hg vacancy formation, and the experimental employment of excess elemental mercury in the system. The close agreement between computed and observed (vertical, stabilizing conditions) mass transport rates supports the validity of this model.
    Additional Material: 4 Ill.
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    URL: http://dx.doi.org/10.1002/zaac.19875450212
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    Umsetzungen von Tetrafluor-1,2-ethandisulfenyldichlorid mit Ketonen und Olefinen (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 545 (1987), S. 143-147 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactions of Tetrafluoro-1, 2-ethanedisulfenyldichloride with Ketones and OlefinesThe reaction of ClSCF2CF2SCl 1 with (CH3)3C—C(O)CH3, hexene, diacetyl, cyclobutanone, and H2C=CHC(O)CH3 leads to the cyclic and acyclic products 2-6. They are destillable liquids, which have been characterized on the basis of elemental analysis, mass spectra, 19F-, 13C-, and 1H-n.m.r. spectra. The reaction mechanism will be discussed.
    Notes: Die Reaktion von ClSCF2CF2SCl 1 mit (CH3)3C—C(O)CH3, Hexen, Diacetyl, Cyclobutanon und H2C=CHC(O)CH3 führt zu den cyclischen und acyclischen Substitutionsprodukten 2-6. Es sind destillierbare Flüssigkeiten, die anhand von Elementaranalysen, Massenspektren, 19F-, 13C- und 1H-NMR-Spektren charakterisiert wurden. Der Reaktionsmechanismus wird diskutiert.
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    URL: http://dx.doi.org/10.1002/zaac.19875450216
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    Magnetische Eigenschaften von Ti3-xMxO5-Phasen (M = V3+, Cr3+, Nb4+) (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 545 (1987), S. 134-142 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Magnetic Properties of Ti3-xMxO5 Phases (M = V3+, Cr3+, Nb4+)The magnetic properties of Ti3-xVxO5, Ti3-xCrxO5, and Ti3-xNbxO5 phases are reported. In the case of V3+ and Cr3+ the magnetic leaping-temperature decreases, however Nb4+ shift the phase-transition towards higher temperatures. All samples show a “memory-effect” in magnetic properties, i. e. the results of heating- and cooling-cycles are higher susceptibilities of the α-phase of Ti3O5. Endowed Ti3O5 phases show for the α- and β-Ti3-xMxO5 til the leap Curie-Weiss characteristic in 1/X vs. temperature measurements. Exception is β-Ti3-xNbxO5, its susceptibility is independend of the temperature up to x ≤ 0.3.
    Notes: Es wird über die magnetischen Eigenschaften von Ti3-xVxO5, Ti3-xCrxO5 und Ti3-xNbxO5 berichtet. Für V3+ und Cr3+ verschiebt sich die magnetische Sprungtemperatur zu kleineren Werten, Nb4+ dagegen verlagert den Phasenübergang in Richtung höherer Temperaturen. Alle Präparate zeigen einen “Gedächtniseffekt” im magnetischen Verhalten, d.h. Aufheiz- und Abkühlzyklen führen zu höheren Suszeptibilitätswerten der α-Form von Ti3O5. Dotiertes Ti3O5 zeigt für α- und β-Ti3-xMxO5 bis zum Sprung in den 1/X über T-Kurven Curie-Weiss-Verhalten. Ausnahme ist β-Ti3-xNbxO5, dessen Molsuszeptibilität bis x ≤ 0,3 temperaturunabhängig ist.
    Additional Material: 4 Ill.
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    Dimethylaminophosphoniumsalze (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 545 (1987), S. 184-190 
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    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Dimethylaminophosphonium SaltsThe amides and chlorides of phosphoric acid 1 and 2 react with N-chlor-dimethylamine or chlorine, respectively, to dimethylaminophosphonium salts 3 and 4. Phosphor trichloride and N-chlor-dimethylamine as well as dimethylamino-dichloro-phosphine and chlorine react to bis(dimethylamino)-dichloro-phosphonium hexachlorophosphate 7.
    Notes: Aus Phosphorigsäureamiden und -chloriden wurden durch Reaktion mit N-Chlordimethylamin bzw. Chlor die Dimethylaminophosphoniumsalze 3 und 4 dargestellt. Die Reaktion von Phosphortrichlorid mit N-Chlordimethylamin bzw. von Dimethylamino-dichlorphosphin mit Chlor führte zum Bis(dimethylamino)dichlorphosphonium-hexachlorophosphat 7.
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    URL: http://dx.doi.org/10.1002/zaac.19875450221
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    Calcium-diazido-di-dimethylformamid, Ca(N3)2[OCHN(CH3)2]2 Darstellung und Kristallstruktur (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 545 (1987), S. 191-196 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Calcium-diazido-di-dimethylformamide, Ca(N3)2[OCHN(CH3)2]2, Preparation and Crystal StructureThe title compound was prepared by the reaction of Ca(N3)2 with OCHN(CH3)2 in aqueous solution. The crystals are orthorhombic, a = 968.5(3), b = 1 479.6(15), c = 1 945.3(17) pm, space group Cmca, Z = 8. The crystal structure was determined by single crystal X-ray diffraction techniques and refined to R = 0.061. Calcium atoms are surrounded by four terminal nitrogen atoms of azide groups and by two oxygen atoms of dimethylformamide (DMF). The polyhedra around Ca are octahedra which are linked via four azide groups to form Ca(N3)2 layers. The DMF molecules are located between these layers, and they are highly disordered.
    Notes: Die im Titel angegebene Verbindung wurde durch Reaktion von Ca(N3) mit Dimethylformamid in wäßriger Lösung hergestellt. Die Kristalle sind rhombisch, a = 968, 5(3), b = 1 479, 6(15), c = 1 945, 3(17) pm, Raumgruppe Cmca, N = 8. Die Kristallstruktur wurde mittels Röntgen-Einkristallmethoden bestimmt und zu R = 0, 061 verfeinert. Die Calciumatome werden oktaedrisch von vier Endstickstoffatomen der Azidgruppen und von zwei Sauerstoffatomen des Dimethylformamids (DMF) umgeben. Die Oktaeder sind über vier Azidgruppen zu Ca(N3)2-Schichten verknüpft. Die DMF-Moleküle befinden sich zwischen den Schichten und sind stark fehlgeordnet.
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    Masthead (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 544 (1987) 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19875440101
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    The System Ga2S3—Pr2O3 (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 545 (1987), S. 197-201 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Das System Ga2S3—Pr2O3Das Zustandsdiagramm des Ga2S3—Pr2O3-Systems wird mittels DTA, HT-DTA, Röntgenphasen-, Mikrostruktur- und thermodynamischer Analysen sowie durch Bestimmung der Mikrohärte untersucht. Das System ist eutektisch, die Löslichkeit auf der Seite des Ga2S3 beträgt 8 Mol.-% bei 295 K. Im System wird die Existenz einer inkongruent schmelzenden Verbindung von Ga2S3 · 2 Pr2O3 gefunden.
    Notes: The diagram of state of Ga2S3—Pr2O3 has been investigated by the methods of differential thermal, high-temperature differential thermal, X-ray diffraction, microstructural and thermodynamic analyses and by measurement of microhardness of the samples. It has been found that the system is eutectic, the solubility on the part of Ga2S3 at 295 K reaches 8 mol.%. In the system the existence of one incongruently-melting compound of Ga2S3 · 2 Pr2O3 was found.
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    URL: http://dx.doi.org/10.1002/zaac.19875450223
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    Zur Darstellung von Alkylammoniumfluoroferraten(III) in wasserfreiem Methanol (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 545 (1987), S. 219-223 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On the Preparation of Alkylammoniumfluoroferrates(III) in Anhydrous MethanolPure Alkylammoniumfluoroferrates(III) can be obtained in good yield by reaction of the corresponding alkylammoniumfluorides with FeBr3 in methanolic solution. Excess of fluoride in the molar ratio F/Fe ≥ 12 yields hexafluoroferrates(III), which rearrange after addition of methanolic FeBr3 solution stepwise to pentafluoroferrates(III) and last not least to tetrafluoroferrates(III). Usually alkylammoniumfluoroferrates(III) are extremely hygroscopic. Above 340 K they decompose forming FeF3, alkylamines, and HF as main products besides small amounts of fluorinated alkylamines.
    Notes: Alkylammoniumfluoroferrate(III) können formelrein und in guter Ausbeute durch Reaktion der entsprechenden Alkylammoniumfluoride mit FeBr3 in methanolischer Lösung dargestellt werden. Bei einem Überschuß an Fluorid (Mol-Verh. F/Fe ≥ 12) werden Hexafluoroferrate(III) gebildet, die bei weiterer Zugabe von FeBr3-Methanollösung über Pentafluoroferrate(III) zu Tetrafluoroferraten (III) abgebaut werden. Die Alkylammoniumfluoroferrate(III) sind in der Regel stark hydrolyseempfindlich; beim Erhitzen zersetzen sie sich ab etwa 340 K unter Bildung von FeF3, Alkylaminen und HF als Hauptprodukten, neben geringen Mengen fluorierter Alkylamine.
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    URL: http://dx.doi.org/10.1002/zaac.19875450226
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    Thermogravimetrische Untersuchungen an Vanadium-komplexen (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 545 (1987), S. 235-240 
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    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Thermogravimetric Investigations of Vanadium ComplexesExtensive studies on oxovanadium(IV) and (V) complexes with bidentate chelating ligands include thermogravimetric investigations. TG, DTG, and DTA data provide additional facts to redox behaviour and stability of the complexes. These data also allow a critical appreciation of the given melting temperatures.
    Notes: Im Rahmen grundlegender Untersuchungen zu Oxovanadium(IV)- bzw. (V)-Komplexen mit zweizähnigen Chelatbildnern werden aus den TG-, DTG- und DTA-Kurven ausgewählter Chelate zusätzliche Daten zum Redoxverhalten und zur Stabilität der Komplexe gewonnen. Die Thermogramme gestatten eine kritische Wertung gemessener Schmelzpunkte.
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    URL: http://dx.doi.org/10.1002/zaac.19875450229
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    Rubidiumhexaamidolanthanat und -neodymat, Rb3[La(NH2)6] und Rb3[Nd(NH2)6]; Strukturverwandtschaft zu K3[Cr(OH6)] und K4CdCl6 (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 546 (1987), S. 42-47 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Rubidium Hexaamidolanthanate and -neodymate, Rb3[La(NH2)6] and Rb3[Nd(NH2)6]; Compounds. Structurally Related to K3[Cr(OH)6] and K4CdCl6Colourless Rb3[La(NH2)6] (a = 12.298(4) Å, c = 13.759(2) Å, N = 6, R3c) and pale blue Rb3[Nd(NH2)6] (a = 12.199(6) Å, c = 13.626(4) Å, N = 6, R32) have been prepared by the reaction of the corresponding metals (Rb: La resp. Nd = 3:1) with NH3(P(NH3) = 4-4.5 kbar) at 300°C. Single crystal x-ray methods gave their structures. It is shown by space group relations that these compounds are structurally related to one another and to further ternary amides as well as to K3[Cr(OH)6] and K4CdCl6.
    Notes: Farbloses Rb3[La(NH2)6] (a = 12,298(4) Å, c = 13,759(2) Å, Z = 6, R3c) und hellblaues Rb3[Nd(NH2)6] (a = 12,199(6) Å, c = 13,626(4) Å, Z = 6, R32) wurden durch Umsetzung der entsprechenden Metalle (Rb: La bzw. Nd = 3:1) mit NH3 (P(NH3) = 4-4,5 kbar) bei 300°C dargestellt. Die Atomanordnung der Verbindungen wurde röntgenographisch an Einkristallen bestimmt. Über Raumgruppenbeziehungen wird die Strukturverwandtschaft zu weiteren ternären Amiden sowie zu K3[Cr(OH)6] und K4CdCl6 erläutert.
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    Verdrillte Tetraederketten ∞1[Li(NH2)4/2-] in der Struktur der hexagonalen Modifikation von Caesiumlithiumamid, CsLi(NH2)2 (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 546 (1987), S. 48-54 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Twisted Tetrahedra Chains ∞1[Li(NH2)4/2-] in the Structure of the Hexagonal Modification of Cesium Lithium Amide, CsLi(NH2)2The ternary amides, CsLi(NH2)2 (dimorphous) and CsLi2(NH2)3, were prepared by reaction of the metals with ammonia in high pressure autoclaves. The structure of the hexagonal modification of CsLi(NH2)2 was established inclusive the hydrogen atom positions from single crystal x-ray data. The compound crystallizes in the space group P6222 with N = 3. The lattice parameters are a = 6.331(1) Å and c = 8.410(1) Å.Lithium ions occupy distorted nitrogen tetrahedra. These tetrahedra are connected by translocated edges along [001]. The cesium ions combine the equally oriented chains ∞1[Li(NH2)4/2-]. The amide ions are twisted out of the hexagonal aa-plane. If we assume sp3-hybridized valence electrons of the nitrogen atoms the bonding interaction between free electron pairs and lithium ions are thereby strenghtened.
    Notes: Ternäre Amide im System CsNH2/LiNH2—CsLi(NH2)2 (dimorph) und CsLi2(NH2)3 - wurden durch Umsetzung der Metalle mit NH3 in Hochdruckautoklaven dargestellt.Die Struktur der hexagonalen Form von CsLi(NH2)2 wurde aus Röntgenbeugungsintensitäten eines Einkristalls einschließlich der H-Atom-Lagen bestimmt. Die Verbindung kristallisiert in der Raumgruppe P6222 mit Z = 3 und den Gitterkonstanten a = 6,331(1) Å und c = 8,410(1) Å.Die Lithiumionen befinden sich in verzerrten Stickstofftetraedern. Diese bilden über transständige Kanten längs [001] Ketten. Die Caesiumionen verknüpfen die gleichsinnig orientierten Ketten ∞1[Li(NH2)4/2-]. Die Amidionen sind aus der hexagonalen aa-Ebene gedreht. Bei einer sp3-Hybridisierung der Valenzelektronen der Stickstoffatome wird dadurch die Wechselwirkung zwischen freien Elektronenpaaren und den Lithiumionen begünstigt.
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    Übergangsmetallphosphidokomplexe. XII. Diphosphenkomplexe (DRPE)Ni[η2-(PR′)2] und die Struktur von (DCPE)NiP(SiMe3)2 (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 546 (1987), S. 79-98 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Transition Metal Phosphido Complexes. XII. Diphosphene Complexes (DRPE)Ni[η2-(PR′)2] and the Structure of (DCPE) NiP (SiMe3)2LiP(SiMe3)2 reacts with the complexes (DRPE)NiCl2 1 (DRPE = R2PCH2CH2PR2; R = Et: DEPE a; R = Cy: DCPE b; R = Ph: DPPE c) to form the diphosphene complexes (DRPE)Ni[η2-(PSiMe3)2] 5a-c. Using low temperature nmr measurements the monosubstitution products (DRPE)Ni[P(SiMe3)2]Cl 2a-c and the disubstitution products (DRPE)Ni[P(SiMe3)2]2 3a, 3c can be detected as intermediates. From the reaction of 1b the paramagnetic nickel(I) complex (DCPE)NiP(SiMe3)2 4b can be isolated. Reacting 1a, 1b with LiP(SiMe3)CMe3 the complexes (DRPE)Ni[P(SiMe3)CMe3]Cl 8a, 8b, which are analogous to 2, and the nickel(0) diphosphine complex (DEPE)Ni[η1-P(SiMe3)CMe3P(SiMe3)CMe3] 9a can be detected n.m.r. spectroscopically, but no diphosphene complexes can finally be isolated. The diphosphene complexes (DRPE)Ni[η2(PPh)2] 10a-c are available from reactions of PhP(SiMe3)2with l a - c. MeP(SiMe,), reacts only with 1b to give a diphosphene complex (DCPE)Ni[η2(PMe)2] 11 b. Reacting [P(SiMe3)CMe3]2 with 1a-c the diphosphene complexes (DRPE)Ni[η2(PCMe3)2] 12a-c can be obtained. 4b crystallizes monoclinic in the space group P2Jc with a = 1228.6 pm, b = 2387.1 pm, c = 2621.8 pm, β = 92.16°, and Z = 8 formula units. The nickel atom is nearly planar coordinated by three phosphorus- atoms, the phosphorus atom of the terminal P(SiMe3)2 group is pyramidally coordinated. The Ni—P bond distances of the two four-coordinated phosphorus atoms are with 219.2 pm and 220.2 pm only slightly shorter than the corresponding distance of the P-atom of the P(SiMe3)2 group with 223.5 pm. N.m.r. and mass spectral data are reported.
    Notes: LiP(SiMe3)2 reagiert mit den Komplexen (DRPE)NiCl2 1 (DRPE = R2PCH2CH2PR2; R = Et: DEPE a; R = Cy: DCPE b; R = Ph: DPPE c) unter Bildung der Diphosphenkomplexe (DRPE)Ni[η2-(PSiMe3)2] 5a-c. Als Zwischenstufen können durch Tieftemperatur-NMR-Messung die Monosubstitutionsprodukte (DRPE)Ni[P(SiMe3)2]Cl 2a-c und die Disubstitutionsprodukte (DRPE)Ni[P(SiMe3)2]2 3a, 3c nachgewiesen werden. Bei der Umsetzung von 1b lässt sich der paramagnetische Nickel(I)-Komplex (DCPE)NiP(SiMe3)2 4b isolieren. Bei den Reaktionen von 1a, 1b mit LiP(SiMe3)CMe3 lassen sich NMR-spektroskopisch die zu 2 analogen Komplexe (DRPE)Ni[P(SiMe3)CMe3]Cl 8a, 8b und der Nickel(0)-Diphosphankomplex (DEPE)Ni[η1-P(SiMe3)CMe3P(SiMe3)CMe3] 9a nachweisen, aber keine Diphosphenkomplexe als Folgeprodukte isolieren. Die Diphosphenkomplexe (DRPE)Ni[η2-(PPh)2] 10a-c sind durch Reaktionen von PhP(SiMe3)2 mit 1a-c erhältlich. MeP(SiMe3)2 reagiert nur mit 1b zu einem Diphosphenkomplex (DCPE)Ni[η2-(PMe)2] 11b. Durch Umsetzungen von [P(SiMe3)CMe3]2 mit 1a-c sind die Diphosphenkomplexe (DRPE)Ni[η2-(PCMe3)2] 12a-c zugänglich. 4b kristallisiert monoklin in der Raumgruppe P21/c mit a = 1228,6 pm, b = 2387,1 pm, c = 2 621,8 pm, β = 92,16° und Z = 8 Formeleinheiten. Das Nickel wird von drei Phosphoratomen nahezu planar koordiniert. Der Phosphor der terminalen P(SiMe3)2-Gruppe ist pyramidal koordiniert. Die Ni—P-Abstände der beiden vierfach koordinierten Phosphoratome sind mit 219,2 pm und 220,2 pm nur wenig kürzer als der Abstand zum P-Atom der P(SiMe3)2-Gruppe mit 222,5 pm. NMR-spektroskopische und massenspektrometrische Daten werden mitgeteilt.
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    Zur Reaktivität von Natrium-dialkylphosphonoformiaten (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 546 (1987), S. 142-146 
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    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On the Reactivity of Sodium DialkylphosphonoformatesThe reaction of sodium dialkylphosphonates with CO2 forming sodium dialkylphosphonoformates, (RO)2P(O)C(O)ONa, I, as well as the further reaction of I are described, 14C-isotope exchange and the n.m.r. spectra are discussed.
    Notes: Die Reaktion von Natrium-dialkylphosphiten mit CO2 zu Natrium-dialkylphosphonoformiaten, (RO)2P(O)C(O)ONa, I, und deren Folgereaktionen werden beschrieben. 14C-Isotopenaustausch und NMR-Spektren werden diskutiert.
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    Komplexe mit substituierten 2,5-Dihydroxy-p-benzochinonen: EAC6(C6H5)2O4 · 4 H2O (EA = Sr2+, Ba2+) (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 546 (1987), S. 152-160 
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    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Complexes with Substituted 2,5-Dihydroxy-p-benzochinones: EAC6(C6H5)2O4 · 4 H2O (EA = Sr2+, Ba2+)Single crystals of the isotypic compounds EAC6(C6H5)2O4 · 4 H2O were grown in aqueous silicagel. EA2+ has CN 8. It is surrounded by four water molecules and four oxygen atoms of the bis-chelating polyporate dianions. Thereby folded chains are formed which are interlinked by hydrogen bonds. Thus building up corrugated layers with the phenyl substituents almost perpendicular to the layer plane. The layer stacking provides that they can engage into another.
    Notes: Einkristalle der isotypen Verbindungen EAC6(C6H5)2O4 · 4 H2O wurden in wässerigem Kieselgel gezüchtet. EA2+ besitzt KZ 8. Es ist von 4 Wassermolekülen und 4 Sauerstoffatomen der als Bis-chelatliganden agierenden Polyporatdianionen umgeben. Dadurch bilden sich gefaltete Ketten, die miteinander durch Wasserstoffbrückenbindungen verbunden sind. Die Phenylsubstituenten stehen annähernd senkrecht auf den hierdurch entstandenen gewellten Schichten. Die Schichtabfolge ermöglicht ein platzsparendes Verzahnen der Schichten.
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    [ReCl3(NSCl)2(CH3CN)]. Synthese, IR-Spektrum und Kristallstruktur (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 546 (1987), S. 177-182 
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    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: [ReCl3(NSCl)2(CH3CN)]. Synthesis, I. R. Spectrum, and Crystal StructureBlack, moisture sensitive crystals of the title compound are obtained from [ReCl3(NSCl)2]2 and acetonitrile in dichloromethane. The complex is characterized by its i.r. spectrum and an X-ray crystal structure determination (2483 observed independent reflexions, R = 0.035). Crystal data: triclinic, space group P1, Z = 2, a = 681.8, b = 899.9, c = 1104.0 pm, α = 110.50, β = 97.90 and γ = 101.34°. In the monomeric [ReCl3(NSCl)2(CH3CN)] molecule the Re atom has a distorted octahedral coordination with meridional arrangement of the Cl atoms. The chlorothionitrene ligands have nearly linear ReNS groups with bond lengths that correspond to double bonds (ReN 178 and 179 pm); this agrees with the NReN bond angle of 100°.
    Notes: Die Titelverbindung entsteht in Form schwarzer, feuchtigkeitsempfindlicher Kristalle aus [ReCl3(NSCl)2]2 und Acetonitril in Dichlormethan. Der Komplex wird durch das IR-Spektrum und durch eine röntgenographische Strukturbestimmung charakterisiert. [ReCl3(NSCl)2(CH3CN)] kristallisiert triklin in der Raumgruppe P1 mit Z = 2 und den Gitterkonstanten a = 681,8; b = 899,9; c = 1104,0 pm; α = 110,50°; β = 97,90°; γ = 101,34° (2483 unabhängige beobachtete Reflexe, R = 3,5%). In dem monomeren Molekülkomplex ist das Rheniumatom verzerrt oktaedrisch von drei meridional angeordneten Chloratomen, von dem N-Atom des Acetonitrilliganden und von den N-Atomen der beiden cis-ständigen Chlorthionitrengruppen umgeben. Die ReN-Abstände der ReNSCl-Gruppen entsprechen Doppelbindungen (178 bzw. 179 pm); im Einklang hiermit beträgt der NReN-Bindungswinkel 100°.
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    Präparative Trennung und quantitative Bestimmung von catena-Phosphaten(V) mit Flüssigkeits-Chromatographie (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 546 (1987), S. 217-228 
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    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Separation on a Preparative Scale and Quantitative Aanalysis of Oligophosphates by Means of Liquid ChromatographyNew methods for the chromatographic analysis and isolation of oligophosphates have been developed. The qualitative separation has been optimized for thin layer chromatography. Quantitative analysis and isolation of the various oligophosphate species has been achieved using liquid chromatography. For ion exchange and molecular sieve-gel columns packing material, column parameters, and eluent were optimized. The on line detection system included a differential refractometer coupled to a strip chart recorder.The applicability of the technique was demonstrated by the quantitative analysis of oligophosphate mixtures. Good reproducibility and accuracy was found. It has been ascertained that the stability of polyphosphates is sufficient to allow efficient separations.
    Notes: Es wurden neue Verfahren für die chromatographische Bestimmung und Isolierung von Oligophosphaten entwickelt. Qualitative Trennungen wurden an Ionenaustauscherfolien und Cellulose-Dünnschichtfolien optimiert. Mit Flüssigkeits-Säulenchromatographie wurden erstmals quantitative Bestimmungen und Trennungen von Oligophosphaten im präparativen Maßstab realisiert. Für die selbstgepackten Ionenaustauscher- und Molekularsieb-Gelsäulen (Niederdruckbereich) wurden Packungsmaterialien, Säulenparameter und Elutionsmittelgemische optimiert. Die Detektion erfolgte „on line“ mit einem Differential-Refraktometer.Die Anwendbarkeit der entwickelten Verfahren wurde durch quantitative Bestimmungen von Oligophosphatgemischen belegt. Die Wiederfindungsraten weisen eine gute Reproduzierbarkeit der Verfahren aus. Es wird gezeigt, daß die Hydrolysebeständigkeit der Phosphate unter den gewählten Trennbedingungen hinreichend groß ist, um eine einwandfreie Isolierung einzelner Spezies zu gewährleisten.
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    Salze von Halogenophosphorsäuren. XV. Sulfan-α,ω-diyl-bis(fluorodithiophosphate), Reaktionsprodukte des Fluoridabbaus schwefelreicher PhosphorsulfideProfessor Wolfgang Wieker zum 60. Geburtstage am 19. April 1987 gewidmet (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 547 (1987), S. 83-90 
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    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Salts of Halogenophosphoric Acids. XV. Sulfane-α,ω-diyl-bis(fluorodithiophosphates). Products of the Fluoride Degradation of Sulfur-rich Phosphorus SulfidesBy the reaction of sulfur-rich phosphorus sulfides „P4S10+m“ (m = 0,5 to 6) with fluorides MF (M = Na, K, NH4) in acetonitrile or 1,2-dimethoxy-ethane mixtures of sulfane-α,ω-diyl-bis(fluorodithiophosphates) [(PFS2)2Sn]2- (n = 1 to 8) are formed. The average chain length n of the sulfane derivatives depends on the S:P ratio of the starting phosphorus sulfides. The compounds are identified by 19F and 31P n.m.r. spectroscopy.
    Notes: Sulfan-α,ω-diyl-bis(fluorodithiophosphate) [(PFS2)2Sn]2-, n = 1 bis 8, entstehen als Gemische bei der Reaktion schwefelreicher Phosphorsulfide „P4S10+m“, m = 0,5 bis 6, mit Fluoriden MF (M = Na, K, NH4) in Acetonitril bzw. 1,2-Dimethoxy-ethan. Die Verteilung der Komponenten dieser homologen Reihe, die 19F- und 31P-NMR-spektroskopisch charakterisiert wurden, hängt vom S:P-Verhältnis des eingesetzten Phosphorsulfids ab.
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    Über den Einfluß von Kristallkeimen auf die Bildung von Silicaten der Zusammensetzung 3 CaO · 2 SiO2Professor Wolfgang Wieker zum 60. Geburtstage am 19. April 1987 gewidmetFür ihre experimentelle Mitarbeit sei auch an dieser Stelle Frau R. Rosenbaum gedankt. (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 547 (1987), S. 118-126 
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    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On the Influence of Seed Crystals on the Formation of Calcium Silicates with the Composition 3 CaO · 2 SiO2The formation of the calcium silicates kilchoanite and rankinite of the composition 3 CaO · 2 SiO2 is facilitated and enabled, respectively, in the presence of appropriate seed crystals. Kilchoanite (Ca6[(SiO4)(Si3O10)]) is formed from mixtures of CaO and SiO2 in the autoclave at 200°C and from C—S—H (di, poly) under normal atmosphere at 700°C by seeding for example with kilchoanite, aluminium compounds, γ-Ca2SiO4. Rankinite (Ca3Si2O7) can be synthesized under the same conditions, when rankinite itself is applied as seed crystal.
    Notes: Es wird gezeigt, daß die Bildung der Calciumsilicate Kilchoanit und Rankinit der Zusammensetzung 3 CaO · 2 SiO2 in Gegenwart entsprechender Impfkristalle erleichtert bzw. erst ermöglicht wird. Kilchoanit (Ca6[(SiO4)(Si3O10)]) bildet sich z. B. durch Animpfen mit Calciumaluminaten, γ-Ca2SiO4 und Kilchoanit aus CaO und SiO2 im Autoklaven bei 200°C und aus C—S—H(Di, Poly) unter Normaldruck oberhalb 700°C. Rankinit (Ca3Si2O7) entsteht unter den gleichen Bedingungen, wenn als Impfkristall Rankinit selbst eingesetzt wird.
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    Salze und Ester der 1,2-Hydrazin-bis(thiocarbonsäure) Kristallstrukturen von K2[OSC—N2H2—CSO] · 2 H2O, CH3S—CO—N2H2—CO—SCH3 und CH3O—CS—N2H2—CS—OCH3 bei 140 K (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 547 (1987), S. 158-166 
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    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Salts and Esters of 1,2-Hydrazin-bis(thiocarboxylic)acid. Crystal Structures of K2[OSC—N2H2—CSO] · 2 H2O, CH3S—CO—N2H2—CO—SCH3, and CH3O—CS—N2H2—CS—OCH3 at 140 KThe anion [OSC—N2H2—CSO]2- and the molecules CH3S—CO—N2H2—CO—SCH3 and CH3O—CS—N2H2—CS—OCH3 exhibit nonplanar structures in the solid state. The dihedral angles beetween either of the two strictly planar R—CX—NH groups of each molecule are 78.8°, 77.5°, and 104.5°, respectively. The N—N bond lengths are 138.5 pm in all three compounds. The N—H groups participate in hydrogen bonds.
    Notes: Das Anion von K2[OSC—N2H2—CSO] · 2 H2O, sowie die Moleküle CH3S—CO—N2H2—CO—SCH3 und CH3O—CS—N2H2—CS—OCH3 besitzen im festen Zustand nichtplanare Konformationen. Die Diederwinkel zwischen den beiden jeweils planaren Molekülhälften betragen 78,8°, 77,5° bzw. 104,5°. Die N—N-Bindungslänge beträgt übereinstimmend in den drei Verbindungen etwa 138,5 pm. Die N—H-Gruppen sind an Wasserstoffbrückenbindungen beteiligt.
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    Dimethyl-N-Fluroamin und -Bortrihalogenid-Addukte sowie Dimethyl-N-Fluorammonium-Salze (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 550 (1987), S. 133-139 
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    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Dimethyl-N-Fluoroamine, Dimethyl-N-Fluoroamine Boron Trihalide Adducts, and Dimethyl-N-Fluoroammonium SaltsThe vibrational assignment of (CH3)2 NF I is given and compared with the vibrational frequencies of the salts (CH3)2NHF+Cl- II and (CH3)2NHF+CF3SO3- III as well as the adducts (CH3)2NF · BHal3 (Hal = F IV, Cl, V, Br VI). In addition the results of a low temperature crystal structure analysis of V are reported.
    Notes: Es werden die Schwingungsfrequenzen von (CH3)2NF I zugeordent und vergleichend mit den Salzen (CH3)2NHF+Cl- II und (CH3)2NHF+CF3SO3- III und den Addukten (CH3)2NF · BHal3 (Hal = F IV, Cl, V, Br, VI) betrachtet. Ergänzend werden die Ergebnisse einer Kristallstrukturanalyse von V bei 140 K mitgeteilt.
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    Perfluororganotellur-Verbindungen: Neue Untersuchungen zur Darstellung von Te(Rf)2 und CH3TeRf (Rf = C2F5, C3F7, C6F5) (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 550 (1987), S. 162-168 
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    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Perfluoroorgano Tellurium Compounds: New Investigations on the Preparation of Te(Rf)2 and CH3TeRf (Rf = C2F5, C3F7, C6F5)Methyl(perfluoroorgano) tellurium and bis(perfluoroorgano) tellurium compounds are synthesized in high yields from the photochemical or the thermal reactions of (CH3)2 Te with perfluoroorgano iodides in the presence of (C2H5)3N. They are isolated in pure states. Another general method for the preparation of bis(perfluoroorgano) tellurium is the thermal reaction of TeCl4 with bis(perfluoroorgano) mercury. The preparations and properties of the partially new compounds are described.
    Notes: Methyl(perfluororgano)tellur-und Bis(perfluororgano) tellur-Verbindungen werden durch photochemische bzw. thermische Umsetzungen von Dimethyltellur mit Perfluoriodorganica in Gegenwart von (C2H5)3N in hohen Ausbeuten synthetisiert und in reiner Form isoliert. Ein weiteres allgemeines Darstellungsverfahren für Bis(perfluororgano) tellur ist die thermische Reaktion von TeCl4 mit Bis(perfluororgano) quecksilber. Die Darstellungsbedingungen und Eigenschaften der z. T. neuen Verbindungen werden beschrieben.
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    Jahresregister 1986 für die Bände 532-543. (bearbeitet von K.-H. Thiele, Merseburg) (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 550 (1987), S. R1 
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    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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    URL: http://dx.doi.org/10.1002/zaac.19875500802
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    Anweisung zur Benutzung des Registers (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 550 (1987), S. R2 
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    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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    Identification of the main Sulfur Nitrogen Compounds in sulfur ammonia solutions (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 551 (1987), S. 21-32 
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    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Identifizierung der wesentlichen Schwefel-Stickstoffverbindungen in Schwefel-AmmoniaklösungenDurch Vergleich der UV/VIS-Absorptionsspektren der Lösungen von Schwefel sowie von synthetisierten Schwefel-Stickstoffverbindungen in flüssigem Ammoniak und durch Vergleich der Ånderungen der Spektren bei Lichteinwirkung folgern wir, daß S7NH, S4NH und S3NH neben Polysulfiden als Hauptbestandteile in Schwefel-Ammoniaklösungen vorliegen. Die Gleichgewichte zwischen den Verbindungen werden durch photochemische Reaktionen reversibel, durch Ag2S-Ausfällung irreversibel verschoben. Als Endprodukt bei der Ag2S-Ausfällung verbleibt S3N3H in der Lösung, das durch Oxydation in S4N4 übergeht.
    Notes: By comparison of the UV-VIS absorption spectra of solutions of sulfur and of synthesized sulfur nitrogen compounds in ammonia and by comparison of their light induced changes we conclude that S7NH, S4NH and S3NH are besides polysulfides H2Sx the Main compounds in sulfur ammonia solutions. The equilibria between the species are shifted reversibly by photoinduced reactions and permanently by Ag2S precipitation (with AgNO3). As the only and final product on Ag2S precipitation S3N3H is identified which by oxidation forms S4N4.
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    Isomerisierung am Cyclotrisilazan-System - Lithiumsalze und Kontraktionsprodukte (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 548 (1987), S. 89-96 
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    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Isomerisation of the Cyclotrisilazane System  -  Lithium Salts and Contraction Products2,2,4,4,6,6-Hexamethyl- and 2,2,4,4,6,6-hexamethyl-1-trimethylsilyl-cyclotrisilazane (1, 2) react with n-C4H9Li to give the lithium salts 3 and 4. At 30°C 4 isomerizes in solution to the cyclodisilazane 5 within 15 h. 4 reacts with Me2SiF2 to the substituted compound 6, whose Li salt contracts yielding the coupled product 7. 1,3-Bis(fluorodimethylsilyl)-2,2,4,4,6,6-hexamethylcyclotrisilazane isomerizes to the Li salt of the corresponding cyclodisilazane, which reacts with the half-molar quantity of SiF4 to the Si—N—Si—N—Si bridged cyclodisilazane dimer 8. The tendency of contraction of 4 is discussed on the basis of its crystal structure.
    Notes: 2,2,4,4,6,6-Hexamethyl- und 2,2,4,4,6,6-Hexamethyl-1-trimethylsilylcyclotrisilazan (1, 2) reagieren mit n-C4H9Li zu den Lithiumsalzen 3 und 4. 4 isomerisiert in Lösung bei 30°C innerhalb von 15 h zum Cyclodisilazan 5. Mit Me2SiF2 reagiert 4 unter Substitution zu 6, dessen Li-Salz kontrahiert und das Kopplungsprodukt 7 bildet. 1,3-Bis(fluordimethylsilyl)-2,2,4,4,6,6-hexamethyl-cyclotrisilazan isomerisiert zum Li-Salz des entsprechenden Cyclodisilazans, das mit der halbmolaren Menge SiF4 zum Si—N—Si—N—Si-verbrückten Cyclodisilazandimer 8 reagiert. Die Kontraktionstendenz von 4 wird anhand der Kristallstruktur diskutiert.
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    Beiträge zur Chemie der Schwefelhalogenide. 16. Dimethyliodsulfonium(IV)-Salze (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 548 (1987), S. 97-102 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Contributions to the Chemistry of Sulfur Halides. 16. Dimethyliodosulfonium(IV) SaltsSome preparative methods of iodosulfonium(IV) salts, (CH3)2SI+AsF6- and (CH3)2SI+SbCl6-, are reported. These salts are stable up to -20°C and they are characterized by Raman and n.m.r. spectroscopy.
    Notes: Es werden mehrere Synthesewege für die Darstellung der Iodsulfonium(IV)-Salze, (CH3)2SI+AsF6- und (CH3)2SI+SbCl6-, angegeben. Diese Salze sind bis -20°C stabil, und sie werden Raman- und NMR-spektroskopisch charakterisiert.
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  • 86
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    PPh3Me[MoBr5(CH3CN)]. IR-Spektrum, magnetisches Verhalten und Kristallstruktur (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 548 (1987), S. 117-124 
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    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: PPh3Me[MoBr5(CH3CN)]. I.R. Spectrum, Magnetic Behaviour, and Crystal StructureMolybdenum tetrabromide and acetonitrile form MoBr4(CH3CN)2, from which PPh3Me[MoBr5(CH3CN)] is obtained by reaction with PPh3MeBr in dibromo methane. Both compounds are characterized by their IR spectra. By evaluation of the magnetic susceptibility of PPh3Me[MoBr5(CH3CN)] in the temperature range of 4.2 to 290 K the Curie-Weiss parameters μcw = 2.65 B.M. and Θ = -44 K were obtained. The crystal structure of PPh3Me[MoBr5(CH3CN)] was determined by X-ray diffraction (2426 observed reflexions, R = 0.082). Crystal data: a = 1064.9, b = 2172.1, c = 1330.4 pm, β = 119.92º, space group P21/c, Z = 4. In the crystal, PPh3Me+ and [MoBr5(CH3CN)]- ions are packed in alternate cation and anion layers perpendicular to a. In the anion the Mo atom has a distorted octahedral coordination. The bond length of the bromine atom in trans position to the N atom is considerably shorter than the other MoBr distances.
    Notes: Das aus Molybdäntetrabromid und Acetonitril gebildete MoBr4(CH3CN)2 reagiert mit Triphenylmethylphosphoniumbromid in Dibrommethan zu PPh3Me[MoBr5(CH3CN)]. Beide Addukte werden durch ihre IR-Spektren charakterisiert. Die Auswertung der Messung der magnetischen Suszeptibilität von PPh3Me[MoBr5(CH3CN)] im Temperaturbereich von 4,2 bis 290 K ergibt die Curie-Weiss-Parameter μcw = 2,65 B.M. und Θ = -44 K. Die Kristallstruktur von PPh3Me[MoBr5(CH3CN)] wurde mittels Röntgenbeugung bestimmt (2426 beobachtete Reflexe, R = 8,2%). Kristalldaten: a = 1064,9, b = 2172,1, c = 1330,4 pm; β = 119,92º, Raumgruppe P21/c, Z = 4. Im Kristall sind PPh3Me+- und [MoBr5(CH3CN)]--Ionen abwechselnd zu Schichten senkrecht zu a gepackt. Im Anion ist das Mo-Atom verzerrt oktaedrisch koordiniert. Der Bindungsabstand des Br-Atoms in trans-Stellung zum N-Atom ist deutlich kürzer als die übrigen Mo—Br-Abstände.
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    Hochtemperaturhydrolyse von PCl3 und PBr3: IR-spektroskopischer Nachweis der matrixisolierten Moleküle OPCl und OPBrBei den hier diskutierten dreiatomigen Molekülen ist in der Formelschreibweise die Reihenfolge der Atome so gewählt, daß die Molekülstruktur deutlich wird. (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 548 (1987), S. 161-164 
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    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: High-Temperature Hydrolysis of PCl3 and PBr3. I.R. Spectroscopic Identification of the Matrix Isolated Molecules OPCl and OPBrAt temperatures of about 700 K PCl3 und PBr3 can be partially hydrolysed in the vapor phase. In the equilibrium gas mixture, cocondensed with an excess of Ar, the molecules OPCl and OPBr are detected by their i.r. spectrum. This observation may be important for reactions of phosphorus trihalides in which traces of water are present.
    Notes: PCl3 und PBr3 können in der Gasphase bei etwa 700 K partiell hydrolisiert werden. Im Hochtemperaturgasgleichgewicht entstehen dabei die Moleküle OPCl und OPBr. Sie werden nach ihrer Kokondensation mit einem Überschuß Argon durch ihr IR-Spektrum nachgewiesen. Diese Beobachtung dürfte für etliche Reaktionen der Phosphortrihalogenide von Bedeutung sein, bei denen Spuren an Feuchtigkeit zugegen sind.
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    Beiträge zur Chemie der Alkylverbindungen von Übergangsmetallen. 50. Eine ungewöhnliche Organolanthanverbindung (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 548 (1987), S. 175-179 
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    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Contributions to the Chemistry of Transition Metal Alkyl Compounds. 50. A non-common Organolanthanum CompoundLanthanum reacts with dibenzyl mercury in tetrahydrofuran as a solvent with splitting of solvent molecules and with formation of ethylene and a benzyl hydrido vinyloxide lanthanum complex of the composition C6H5CH2La(H)OCH=CH2 · 2 THF. This complex, primary well soluble in tetrahydrofuran, is extremely sensitive against air and moisture and undergoes a fast coordination polymerisation with a strong decrease of the solubility.The compound was characterized by elementary analysis, the hydrolysis and deuterolysis reaction, and by the i.r. spectra.
    Notes: Lanthan reagiert mit Dibenzylquecksilber in Tetrahydrofuran als Reaktionsmedium unter Spaltung von Lösungsmittelmolekülen zu Ethylen und einem Benzylhydridovinyloxid-lanthan-Komplex der Zusammensetzung C6H5CH2La(H)OCH=CH2 · 2 THF. Dieser anfangs in Tetrahydrofuran gut lösliche Komplex ist extrem luft- und feuchtigkeitsempfindlich und unterliegt rasch einer Koordinationspolymerisation unter starker Abnahme der Löslichkeit.Die Charakterisierung erfolgte durch Elementaranalyse, Verfolgung der Hydrolyse und Deuterolyse sowie Auswertung des IR-Spektrums.
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    Cyclische Kieselsäurederivate (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 548 (1987), S. 193-203 
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    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Cyclic Silicic Acid DerivativesBy reaction of SiCl4 with oxygen at elevated temperatures a number of chlorsiloxanes consisting of more or less fused rings can be prepared of which those components of low molecular weight can be separated by combining distillation and crystallization. Methyl and ethyl esters of silicic acids are obtained by reaction with methyl or ethyl nitrite, resp. The compounds are characterized by silicon n.m.r. and mass spectroscopy.
    Notes: Bei der Reaktion von SiCl4 mit Sauerstoff bei erhöhter Temperatur entstehen eine große Anzahl von Chlorsiloxanen, die aus mehr oder weniger kondensierten Ringen bestehen. Aus dem niedermolekularen Anteil können eine Reihe von Spezies durch die Kombination von Destillation und Kristallisation isoliert werden. Durch Umsetzung mit Methyl- bzw. Ethylnitrit lassen sich daraus die entsprechenden Ester der Kieselsäuren darstellen. Die Verbindungen werden durch 29Si-Kernresonanz und in gewissem Grade durch die Massenspektrometrie charakterisiert.
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    Oxydation intermetallischer Phasen: Na5InO4 aus Naln und Na2O2 (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 549 (1987), S. 15-25 
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    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Oxidation of Intermetallic Phases: Na5InO4 from NaIn and Na2O2By oxidation of NaIn with Na2O2 [sealed Ag-cylinder 430°C, 1 d] Na5InO4 is formed as light yellow, coarse single crystals. The lattice constants of the orthorhombic cell are: \documentclass{article}\pagestyle{empty}\begin{document}$$ {\rm a = 1071,7}\left({\rm 3} \right)\quad{\rm b = 1055,0}\left({\rm 3} \right)\quad{\rm c = 1080,9}\left({\rm 3} \right){\rm pm, Z = 8} $$\end{document} According single crystal data [Pbca; four-circle diffractometer PW 1100, 1 748 out of 1 769 I0(hkl); R = 6.3% and Rw = 4.5%] Na5InO4 is isotypic with α-Li5GaO4. The Madelung Part of Lattice Energie, MAPLE, the Mean Fictiv Ionic Radii, MEFIR, and the Effectiv Coordination Numbers, ECoN, are calculated.
    Notes: Durch Oxydation von NaIn mit Na2O2 [geschlossener Ag-Zylinder, 430°C, 1 Tag] entsteht Na5InO4 in schwach hellgelben, derben Einkristallen. Die Gitterkonstanten der orthorhombischen Zelle sind: \documentclass{article}\pagestyle{empty}\begin{document}$$ {\rm a = 1071,7}\left({\rm 3} \right)\quad{\rm b = 1055,0}\left({\rm 3} \right)\quad{\rm c = 1080,9}\left({\rm 3} \right){\rm pm, Z = 8} $$\end{document} Nach Strukturaufklärung [Pbca; Vierkreisdiffrakrometer PW 1100, 1 748 von 1 769 I0(hkl), R = 6,3% und Rw = 4,5%] liegt Isotypie mit α-Li5GaO4 vor. Der Madelunganteil der Gitterenergie, MAPLE, die Mittleren Fiktiven Ionenradien, MEFIR, und die Effektiven Koordinationszahlen, ECoN, werden berechnet.
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    Crystal Structure of CH2[N(SO2F)2]2, N,N,N′,N′-tetrakis(fluorosulfuryl)methylenediamineDedicated to Professor Karel Dostál on his 65th Birthday (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 549 (1987), S. 67-72 
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    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Kristallstruktur von CH2[N(SO2F)2]2, N,N′,N,N′-Tetrakis (fluorosulfuryl)methylendiaminCH2[N(SO2F)2]2 ist monoklin, Raumgruppe P21/c, mit Z = 8. Die Struktur, die durch direkte Methoden gelöst und bis zu einem R-Wert von 0,082 für 2647 Diffraktometerdaten verfeinert wurde, besteht aus diskreten Molekülen.
    Notes: CH2[N(SO2F)2]2 is monoclinic, space group P21/c, with 8 molecules in the unit cell. The structure, which was solved by direct methods in a straightforward manner and refined to R = 0.082 for 2647 diffractometer intensities, consists of discrete molecules.
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    Zur Konstitution von ‚KPbO2‘ (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 549 (1987), S. 87-102 
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    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On the Constitution of ‘KPbO2’Transparent, orangered single crystals of K2Pb2O4 have been obtained by heating mixtures of K2O2 and PbO (K:Pb = 1:1) [Ag-cylinders, 560°C, 40 d, after cooling (15°C/h)]. The space group is P1, a = 1295.94(9), b = 753.35(7), c = 697.12(8) pm, α = 118.00(1)°, β = 106.15(1)°, γ = 93.44(1)°, Z = 4, dx = 6.573 und dpyk = 6.54 g · cm3. The structure is characterized by rutilanalogous chains of edge-connected [PbO6] octahedra along [001] according to [PbO4/2O2/1] = PbO4. On both sides of such a chain there are respectively three O2-, which belong to two octahedra, alternating capped with Pb2+ or not capped, corresponding to [PbO4]Pb2[PbO4]□2… = Pb2O4. Those capped chains are held together by K(1)…K(4), each of them with C.N. 6. The order of the chains corresponds to the motive of a closest packing.The Madelung Part of Lattice Energy, MAPLE, Effective Coordination Numbers, ECoN, these via Mean Fictive Ionic Radii, MEFIR, are calculated and discussed.
    Notes: Transparente, orangerot aussehende, Einkristalle von K2Pb2O4 wurden aus Gemengen von K2O2 und PbO (K:Pb = 1:1) durch Tempern [Ag-Bömbchen, 560°C, 40 d, nach Abkühlen (15°C/h)] erhalten. Sie sind triklin, P1, a = 1295,94(9), b = 753,35(7), c = 697,12(8) pm, α = 118,00(1)°, β = 106,15(1)°, γ = 93,44(1)°, Z = 4, drö = 6,573 und dpyk = 6,54 g · cm3. Strukturcharakteristisch sind Rutil-analoge Stränge kantenverknüpfter [PbO6]-Oktaeder längs [001] gemäß [PbO4/2O2/1] = PbO4. Jeweils beidseitig eines solchen Stranges sind je drei O2-, die zwei Oktaedern zugehören, alternierend mit Pb2+ bekappt oder unbekappt, entsprechend [PbO4]Pb2[PbO4]□2… = Pb2O4. Derartige bekappte Stränge werden durch K(1)…K(4), jeweils C.N. 6 zusammengehalten. Die Anordnung der Stränge entspricht dem Motiv einer dichtesten Packung.Der Madelunganteil der Gitterenergie, MAPLE, Effektive Koordinationszahlen, ECoN, diese über Mittlere Fiktive Ionenradien, MEFIR, werden berechnet und diskutiert.
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    Ein neues Periodat Zum Aufbau von K9Li3I2O13 = K9Li3O[IO6]2 (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 549 (1987), S. 129-138 
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    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: A Novel Periodate: On the Structure of K9Li3I2O13 = K9Li3O[IO6]2New obtained are weakly dichroitic (pale yellow/bluish) single crystals of K9Li3I2O13 by reaction of KIO4, K2O, and Li2O (KIO4:K2O:Li2O = 1:1:1.5; 800°C, 42 d). Space group P62c, Z = 2, a = 954.9 pm, c = 1172.2 pm, R = 6.2%, Rw = 5.6%, 957 symmetry independend I0(hkl), MoKα. Characteristic for this structure are „isolated“ O2- and octahedral groups [IO6]. The crystal structure has been determind. The Madelung Part of Lattice Energy, MAPLE, is calculated and discussed.
    Notes: Neu dargestellt wurde aus KIO4, K2O und Li2O in Form schwach dichroitischer (gelblich/bläulich) Einkristalle K9Li3I2O13 (KIO4:K2O:Li2O = 1:1:1,5; 800°C, 42 d) Raumgruppe P62c, Z = 2, a = 954,9 pm, c = 1172,2 pm, R = 6,2%, Rw = 5,6% für 957 symmetrieunabhängige Reflexe, MoKα. Charakteristisch für die Struktur sind neben „isolierten“ O2- oktaedrische Gruppen [IO6]. Die Struktur wird beschrieben und der Madelunganteil der Gitterenergie, MAPLE, berechnet und diskutiert.
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    Cobaltchelate als Hydrierkatalysatoren. III. Die Hydridbildung des [Co(dpnH)]+-Komplexes in Gegenwart von Pyridin als axialer Base (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 549 (1987), S. 160-170 
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    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Cobalt Chelates as Hydrogenation Catalysts. III. Hydride Formation of the [Co(dpnH)]+ Catalyst in the Presence of Pyridine as Axial BaseThe rate of the hydrogen uptake for [Co(dpnH)]+ is 2nd order with respect to the complex concentration and depends on the amount of added pyridine, in accord with the assumption of a more active mono- and an inactive bis-pyridine adduct. The rate law, formulated on this basis agrees very well with the measured data. The ΔH≠ - and ΔRH°-values, calculated from the temperature dependence of the rate constants and equilibrium constants are in agreement with the suggested model, whereas the ΔS≠ and ΔRS° values do not correspond completely with these expectations.
    Notes: Die Geschwindigkeit der Wasserstoffaufnahme des [Co(dpnH)]+-Komplexes ist 2. Ordnung bezüglich der Komplexkonzentration und abhängig von der Menge an zugesetztem Pyridin, in Übereinstimmung mit der Annahme eines aktiveren Mono- und eines inaktiven Bis-Pyridinaddukts. Das auf dieser Basis formulierte Geschwindigkeitsgesetz steht in sehr guter Übereinstimmung mit den Meßwerten. Die aus der Temperaturabhängigkeit der Geschwindigkeits- bzw. Gleichgewichtskonstanten berechneten ΔH≠- und ΔRH°-Werte stimmen mit dem angenommenen kinetischen Modell überein, während die ΔS≠- und ΔRS°-Werte diesen Erwartungen nicht ganz entsprechen.
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    Synthese und Kristallstruktur von (PPh4)2[Mo2NCl9]2, einem μ-Nitridokomplex mit Molybdän(V), und -(VI) (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 554 (1987), S. 92-100 
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    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis and Crystal Structure of (PPh4)2[Mo2NCl9]2, a μ-Nitrido Complex with Molybdenum (V) and (VI)The title compound is formed as a by-product in the partial oxidation of Mo2NCl7 with chlorine in POCl3 solution, when the reaction mixture is treated with PPh4Cl. The crystals, which are sensitive to moisture, are black in reflectance and red in transmittance. A more effective synthesis is the direct reaction of PPh4[MoNCl4] with MoCl5 in dichloro methane. (PPh4)2[Mo2NCl9]2 was characterized by the i.r. spectrum and by a structural analysis with X-ray data. The compound crystallizes triclinic in the space group P1 with two formula units per unit cell (9225 independent observed reflexions, R = 0.058). The cell parameters are (20°C): a = 1144 pm, b = 1517 pm, c = 2000 pm, α = 79.8°, β = 80.1°, γ = 72.1°. (PPh4)2[Mo2NCl9]2 consists of PPh4⊕ cations and the anions [Mo2NCl9]222⊖, which dimerize via chloro bridges with Mo—Cl bons lengths of 243 pm and 287 pm. In the [Mo2NCl9]22- units the molybdenum atoms are linked by MoVI≡N—MoV bridges (bond angles 179° and 174°, resp.) with Mo—N bond lengths of 167 pm and 212 pm.
    Notes: Die Titelverbindung entsteht als Nebenprodukt bei der partiellen Oxidation von Mo2NCl7 in POC3-Lösng mit Chlor und anschließender Umsetzung mit PPh4Cl in Form schwarzer, in der Durchsicht roter, feuchtigkeitsempfindlicher Kristalle. Zur Synthese besser geignet ist die direkte Umsetzung von PPh4[MoNCl4] mit MoCl5 in Dichlormethan-Lösng. (PPh4)2[Mo2NCl9]2 wurde durch das IR-Spektrum und durch eine röntgenographische Strukturanalyse charakterisiert. Die Verbindung kristallisiert triklin in der Raumgruppe P1 mit zwei Formeleinheiten pro Elementarzelle (9225 unabhängige, beobachtbare Reflexe, R = 5,8%). Die Gitterkonstanten sind bei 20°C: a = 1144, b = 1517, c = 2000 pm, α = 79,8°; β = 80,1°; γ = 72,1°. (PPh4)2[Mo2NCl9]2 besteht aus PPh4⊕-Kationen und Anionen Mo2NCl9⊖, die über zwei Chlorobrücken mit Mo—Cl-Abständen von 243 und 287 pm dimerisieren. In den Mo2NCl9⊖-Einheiten sind die Molybdänatome über gestreckte MoVI≡N—MoV -Brücken (Bindungswinkel 179° bzw. 174°) mit MoN-Abständen von 167 bzw. 212 pm verknüpft.
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    Zum chemischen Transport von MnCl2 mit MeCl3 (Me = Al, Ga, In) (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 550 (1987), S. 123-132 
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    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On the Chemical Transport of MnCl2 with MeCl3 (Me = Al, Ga, In)The transport behaviour of MnCl2 with MeCl3 (Me = Al, Ga, In) has been calculated by the aid of the solubilities in the gas phase taking into account the gaseous chlorid complexes MnMeCl5, MnMe2Cl8, and MnMe3Cl11 and compared with the experimental results. The transport take place only from hot to cold with InCl3, where as a maximum of the solubility of the gas phase exists using AlCl3 and GaCl3. There is a good agreement between the calculated and the experimental results.
    Notes: Das Transportverhalten von MnCl2 mit MeCl3 (Me = Al, Ga, In) wird unter Berücksichtigung der gasförmigen Chloridkomplexe MnMeCl5, MnMe2Cl8 und MnMe3Cl11 über die Gasphasenlöslichkeiten berechnet und mit den experimentellen Ergebnissen verglichen. Während bei Verwendung von AlCl3 und GaCl3 ein Maximum der Gasphasenlöslichkeit auftritt, werden mit InCl3 als Transportmittel nur heiß-kalt-Transporte festgestellt. Die berechneten und experimentellen Ergebnisse zeigen eine gute Übereinstimmung.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19875500714
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  • 97
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    Untersuchungen an Nickeloxid-Mischkatalysatoren. XVI. Reduktionsverhalten amorpher NiO—Al2O3/SiO2-Katalysatoren (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 550 (1987), S. 177-185 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Studies on Nickel Oxide Mixed Catalysts. XVI. Reduction Behaviour of Amorphous NiO—Al2O3/SiO2 CatalystsThe reduction behaviour of NiO—Al2O3/SiO2 catalysts prepared by precipitationdeposition is influenced by the phase composition (amorphous nickel layersilicates and nickel alumino layersilicates, nickel spinels, nickel oxide) and the differences of the composition between surface and bulk. TPR measurements, determinations of the reduction degree, and the nickel particle sizes by static magnetic measurements showed that the reducibility of the NiO—Al2O3/SiO2 catalysts is enhanced and the nickel dispersity is decreased at low Al2O3 contents. The decrease of the reducibility at Al2O3 contents 〉5 mole% is caused by the formation of nickel spinels and the decrease of the NiII ion surface concentration.
    Notes: Das Reduktionsverhalten durch Auffällen hergestellter NiO—Al2O3/SiO2-Katalysatoren wird durch die Phasenzusammensetzung (amorphe Nickelschicht-und alumoschichtsilicate, Nickelspinelle, Nickeloxid) und durch die Unterschiede in der Zusammensetzung zwischen Volumen und Oberfläche bestimmt. TPR-Messungen, Bestimmungen des Reduktionsgrades und der Nickelpartikelgrößen durch statische magnetische Messungen zeigten, daß bei geringen Al2O3-Gehalten die Reduzierbarkeit der NiO—Al2O3/SiO2-Katalysatoren erhöht und die Nickeldispersität vermindert wird. Die Abnahme der Reduzierbarkeit bei Al2O3-Gehalten 〉5 Mol-% wird durch die Bildung von Nickelspinellen und durch die Abnahme der NiII-Ionenoberflächenkonzentration verursacht.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19875500720
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  • 98
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    Zum Kondensationsverhalten von Silanolen. IV. Die sauer katalysierte Kondensation von Organodimethylsilanolen in Dioxan/Wasser (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 550 (1987), S. 186-194 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On the Condensation Behaviour of Silanols. IV. Acid Catalyzed Condensation of Organodimethylsilanols in Dioxane/WaterThe condensation has been followed by GLC for silanols of the type XMe2SiOH in aqueous dioxane with HCl as catalyst. The obtained kinetic data and equilibrium constants are discussed with respect to the substituent dependence and the reaction mechanism.
    Notes: Für Silianole des Typs XMe2SiOH (X = Alkyl, Aryl, Halogenalkyl, Benzyl, Silyl) wurde gaschromatographisch die Kondensation in wäßrigem Dioxan mit HCl als Katalysator verfolgt. Die erhaltenen kinetischen Daten und Gleichgewichtskonstanten werden bezüglich ihrer Substituentenabhängigkeit sowie mechanistischer Aussagen diskutiert.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19875500721
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  • 99
    Electronic Resource
    Electronic Resource
    Zur Kenntnis von Polymetaarseniten Darstellung und Kristallstruktur von BaAs2O4 · H2O (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 554 (1987), S. 137-145 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Concerning Polymetaarsenites. Preparation and Crystal Structure of BaAs2O4. H2OBaAs2O4·H2O was prepared by hydrothermal reaction of BaO with As2O3 at a temperatur of 200°C. An X-ray structural analysis demonstrated that the phase contains polymetaarsenite anions [As4O84-]n, which adopt vierer single chains in the lattice. The relationship between the conformation of metaarsenite chains and cation size is discussed.
    Notes: BaAs2O4·H2O wurde durch hydrothermale Reaktion von BaO mit As2O3 bei einer Temperatur von 200°C dargestellt. Eine Röntgenstruktranalyse ergab, daß die Phase Polymetaarsenitanionen [As4O84-]n beinhaltet, die im Kristallgitter als Vierer-Einfachketten vorliegen. Die Beziehung zwischen Konformation von Polymetaarsenitketten und Kationgröße wird erlätert.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19875541118
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  • 100
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    Untersuchungen zur Bestimmung der Phasenbreite transportierter MnO- Kristalle (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 554 (1987), S. 166-171 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Investigations for Determination of Phase-Extension of Transported MnO-CrystalsWe determined the O/Mn relation of transported MnO crystals with the method of solid electrolyte coulometry. It follows the phase-extension of MnO in function of temperature from 0.0025 at 1091 K to 0.0128 at 1292 K.
    Notes: Das O/Mn-Verhältnis transportierter MnO-Kristalle wurde mit dem Verfahren der Festelektrolytcoulometrie bestimmt. Für MnO ergibt sich eine temperaturabhängige Phasenbreite, die sich von 0,0025 bei 1091 K bis zu 0,0128 bei 1292 K erstreckt.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19875541121
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